So you see the detector is clicking only, you know, roughly once per day. So this makes it really interesting for all kinds of physics where you want to look at very rare events.
One thing that we've been looking at both that this and at JPL is extending the range of operation of SSDs out into the, you, you know, GUV and then also out to, so long wavelengths.
So at JPL, we recently demonstrated SSPs that have this saturated internal detection efficiency out as long as 29 microns.
In the approaching the fire infrared and we are very excited that we actually think that we can tune this even further and push this out to even longer wavelengths.
And we're really excited about that because there is no other technology that does time results, single photon counting or even real single photon counting at these wavelengths, especially beyond 15 microns.
Yes, since you have, low.com. Do you know, what generate?
No, we don't have a good understanding of how the different background mechanisms. You know, we don't have a good understanding of how the different background mechanisms, you know, what, the source of these, are.
Also, I should say we don't, you know, this detector was not, to 29 microns, right?
I mean, as we decrease the energy threshold, I'm sure that we decrease the energy threshold, I'm sure that we will start to open ourselves, I'm sure that we will start to open ourselves up to all kinds of low energy fluctuations to all kinds of lower energy fluctuations and lower energy backgrounds.
So we've, you know, have lots of lower tochy fluctuations and lower energy backgrounds.
So we, you know, have lots of discussions with people, you know, following the literature for, you know, dark matter, what different sources of backgrounds are, how's the phrase, etc.
One thing I will say about the SSP is that is a little bit different from other kinds of super induction detectors.
You might be familiar with like TS is is that we're not sensitive really to cosmic rays in the substrate unless we're not sensitive really to cosmic rays in the substrate, unless the, cause the, you know.
Except for the sunshine that's right underneath the. But like I said, yes, well, you know, scoop up energy from throughout the entire substrate.
So the sort of effective active area for cosmic rays is typically the size of the whole. You know, device the whole way.
Whereas here, you know, you're only really sensitive to, Cost the, the deposit, the energy in the, itself.
So that's one of the reasons why it's possible to get lowered our accounts with a SSPD than it is with a.
If I understand what you're saying. You suspect that this accounts are produced. By external effects and not by internal effects.
This is the efficiency as a function of the bias and you reach this region where it plateau and it's saturated if you go right up to the edge, so you're very close to the switching current, then you can get thermally activated dark counts and those show an exponential dependence that's well known with bias.
But typically if you the fact that you have this plateau means that you can back off of that. And so you can get out of the regime where you have the, thermally activated dark counts and then you hit this kind of floor.
Oh yeah, this kind of shows it. This is, you reach this full, these are the dark counts here.
So you have this floor of our accounts and we're not sure the degree to which those may be caused by issues of the electronics or cosmic rays or other sorts of backgrounds.
This part is still under investigation. I think as we lower the energy threshold, it's gonna be very important to keep.
Okay, also there's been a lot of progress in increasing the size of the arrays.
So our colleagues, we worked on a joint project with our colleagues at NIST who recently demonstrated a really kind of mind-blowing number of SSDs.
So this is an array that use a couple of different layers of time, domain multiplexing. And this actually had 400,000 SSPD pixels in an array for time resolved imaging.
So this was recently, published in Nature, about a month ago and, this really represents a big advance forward in putting SSPs for the first time in the same kind of playing field as semiconductor detectors in terms of the kind of pixel formats.
What kind of efficiencies? This has miserable efficiency because it's not any kind of cavity and it's it's the pixel sizes is really small it's basically one by one micron however you know we're trying to in a level of multiplex.
One by one micron in itself is not a problem. On film factor. It's high. The fact is not that high. It's 5.
I saw a 5 micron. So it's so this was a proof of concept to show that the multiplexing could work to get you to 400,000 pixels.
It's a proof of concept to show that the multiplexing could work again. 400,000 pixels.
It's a no way a detector you want to really use in an imaging application. It's in no way a detector you want to really use in an imaging application or space telescope.
So we, there's lots of work to go in the future to make this detector efficient and, at our space. Telescope.
So we, there's lots of work to go in the future to make this detector efficient and, work at short, and everything else.
Also, the count rate across this detector was pretty low, like across these 400,000 pixels, you can only count at 10 to the 5 counts per second across the whole array.
So however for certain kinds of applications where fluxes are really low, such as exoplanet, astronomy and things like that.
It's still. Quite interesting and there's a lot of tricks. So it's the beginning.
Not the, yeah. There was some work we did a few years ago. Now, of course, was a post doc, to try to push the, time resolution of the SSD down to, really, small bottles.
And so we were able to show during the DARPA program that we were able to get below 3 pico second timing resolution at indivisible and below 5 because I can sign a resolution at 1550.
Then use with that max using a kind of a specialized. Ssd structure. And then one thing I'll talk about this talk, if I, would be to, make SSPs which are optimized for quantum communication, which are optimized for quantum communication on how high clock rates.
While maintaining 100 per second time resolution. So it's exactly what you want if you're trying to do quantum calm at a 10 gigahertz clock.
So, and I'll talk more about these, these peacock shape detectors.
Which is on the Okay, thank you. Alright, just very briefly. I probably don't have to tell you, but yes, that's the user useful for optical communication, on information science, astronomy applications.
This is we're exploring biomedical imaging applications, especially when you start to go to medical imaging applications, especially when you start to build a large rays, other remote sensing applications, especially when you start to build a large, other remote sensing applications of SSPs and relevant to FRAME, for the, so we're working with some folks at Fermi Lab on, some
dark matter detection experiment. So this project here called Red. Which, Christian is, and other folks at Fermi Lab are trying to, it's great to, and the Jamie is doing her PhD research, looking at dark.
I'm doing her PhD research, looking at dark matter detection using Gallium Arseni.
And then there's also a joint for the LED, Crystals. And then there's also a joint for the, project that's just, getting started, to try to do a table talk test to try to do a tabletop test of one gravity called GEEQUE, to try to do a tabletop test with one gravity called GEEPS which relies on the low
darkouts. Yeah. Okay, so, one of the things, so now I'm gonna talk about SSDs for communication.
And, mostly for quantum communication, and, mostly for quantum communication, but I also just wanted to talk about SSDs for communication, and, mostly for quantum communication, but I also just wanted to advertise some of the free space possible communication that we've been using, the SSDs were, in part because Space.
Ground quantum communication is also very relevant and at the end of the day it's a lot of the same technology.
Tracking spacecraft, counting photons one at a time, etc. So one of the things we've been doing at JPL is using these detectors in different ground stations for free space optical communication demonstrations.
We're working on 2 tech demos. Right now, one, is called, which is, we're very excited about, which is the, the deep space optical communication technology demonstration.
So this is the first demonstration of free space. Laser communication from interplanetary space. Actually just launched on October thirteenth and we actually are just getting the first results back in the last couple of weeks.
For that we built a fancy, what are they? Are they saying we're under attack or?
Is it encoded? Yes, I'll show you actually how they works. But the, oh, that kind of coded. Hmm? Is it encoded?
Yes, I'll show you actually how they works. But the, oh, that kind of a coded.
Is it encoded? Yes, I'll show you actually how the, works. But the, oh, that kind of The longest range demonstration of free space.
Opticalcom that has been done so far was from the moon to the earth in 2,013 the lunar It's led by Lincoln and daughter, There, you know, the moon is about 400,000 kilometers, you know, away at over take.
Dsock is on a spacecraft going to the asteroid belt called psyche which is where and the common system is designed to work out to about 400 million kilometers.
So it's beyond bars far this range. So it's a thousand times longer than any previous laser calm demo, which means it's actually a million times harder because, one of our square.
So there are actually a lot of new technologies that went into DSO. There's an active vibration isolation platform on the spacecraft, which was the first time that those kind of magnetic isolation, the pointing requirements are, pretty extreme.
You know, and the spot size when you're out of the longest, requirements are, pretty extreme, you know, and the spot size when you're having the longest, ranges is about a thousand kilometers in So this is telling you why you need a single photon detector on the ground because even a 5 metre telescope is a tiny tiny little
pinhole and just 1,000 kilometer laser. And so we were really really excited. That You know, we were able to put this all together and have it all work.
But we also have built round terminals for other, optical calm demos, at other locations as well.
You can go to the next slide. So I just wanted to very briefly explain how DSock works a tiny bit.
We use this pulse position modulation as a way to You know what? Actually, I only have 5 min. I'll skip this slide.
Most people are really, you people understand. Do they want to hear about this? Go ahead, why not?
Okay, I feel, alright, alright. Well, you, you could do the other thing and then come back.
Since we don't know, we don't know. We don't know. I was gonna talk about the detectable detector, probably using this.
Yeah, yeah, we'll come back to that. Yeah, yeah, we'll come back to the stuff works.
Yeah, so we need a special SSP rate for DTOCKS. Yeah, so we need a special SSV. Software.
Yeah, so we need a special SSV rate for DSOC, which was a 300 micron diameter active area, a sense video range at 64 nano wires all together.
And so this is large enough to couple to a 5 year telescope with without having to use any adaptive office.
You can go to the next slide. This just shows how it looks, where we have free space office coming into the chrysat.
We actually, the nano wires are meandered around to fill up 4 little quadrants in the active area so it forms a quad cells we can do real time to tell the correction.
And then we have, free space, short pass filters, project temperatures.
We walk out all the infrared block body from the room. And this same setup, so we have a cryogenic lens right in the detector so we can couple a recently fast beam and do basically 200 X, and do basically 200 X.
N. 500 and telescope to, sorry. 200 to a 300 micron.
Detector. Craiginic, blend in this case just means that it's a lens that's in the crisis or something special. No, it's just a normal ordinary lens.
And this is it's in a titanium. And this is it's in a titanium pressure mount so that it stays alive.
And then you can go to the next slide real quick. This just, each SNS the actually has its own, readout line and it's all, frygenic amplifiers.
We have these whole amplifier boards that we can scale up, and we have readout electronics.
It's developed by our colleague, Thomas Laneer, in Austria who, which can keep up with this, flood of data.
So this can actually stream, at 1.5 giga tags per second. And I'll mention, we have another one that's even newer from him.
And I'll mention, he, we have another one that's even newer from him that we're using for another one that's even newer from him that we're using for the quantum cast which can stream at 60 attacks per second across 128 accounts.
Yeah, and he he thinks he can go faster. So Sounds all even that's with the 50 pick a second timing resolution.
No, here we need a DSO has 500 people second slots so we only need like 125 per second.
I mean, like that gives us, still like 4 samples per slap, which is funny.
For other reasons, they didn't want this clock too much faster than that. But, yeah, you can go.
Go ahead. Okay, so this just is showing our, ground terminal. So this is our chrysat with As many people going out into the, the readout electronics, the light comes in to the Alamar Telescope, goes down to this little room that's off to the side of today focused, where, and then there's an optics that does all the,
polarization objects and other things and filter it. And then we free space double directly to surprise that. So, and I should say just last week, we closed for the first time, links at our highest data rates, which were 267 megabits per second streaming down link at point 1 7 AU.
So this is a new record, for sure in terms of distance range for optical calm. And what, what is, what is the moon?
In a, 0 point 0 4. Wow. So it's quite a bit farther and the system is designed to work out to 2.7 A. U.
So, and we won't get 2 67 megabits from 2.7. But, that was, one of the crazy things about this is that we had to do the very highest data links right at the beginning.
One of the crazy things about this is that we had to do the very highest data links right at the beginning in the first few passes.
Because, you know, as the facecap is farther, farther, the data rates go down.
But anyway, in Justin this one, past, we actually downloaded, 1.3 terabits of data, which for record is about 4 years of the cassini.
Data that came back from. So it really does enable a lot in terms of future missions and future, you know, and future, missions and future, missions and future, you know, instruments that people might want to make.
So we're excited about that. You can go to the next slide where make sure this is, so we're excited about that.
You can go to the next slide where I show this is 2 of our operators at the TSAC.
I have a woman who built a lot of this hardware and worked at our group for many years happy to see that this thing actually works.
Okay, so very briefly,
So, okay, now it's a lot of all, believe it or not, already. That's why.
That so are we gonna go completely off the rails here or should I do what do you want to do?
Keep it to go another 5 min. Okay. There's there's 2 contingency is lands and then how late you night dinner.
Okay. So I'm gonna go very very quickly. These are the detectors that just gets us completely off on the wrong foot. So I'm gonna go very, very quickly.
These are the detectors that we're actually So I shouldn't have saved this all. But, such as it is.
So these detectors are detectors which are designed to have a reasonable compromise between the different metrics that I showed you on the first page.
So, these detectors are, detectors, which are designed to have a reasonable compromise between the different metrics that I showed you on the first page.
So the first page, you know, efficiency, everything like that. This is supposed to be a rational compromise, which is useful.
Information. Experiment. So this is uses the self aligned fiber coupling. It's, they're nioga nitride detectors, so they're reasonably fast and they have a couple of unique features.
They have this differential readout. So that cancels out the timing center, which is due to the location along the wire that the photon, that's the geometric tutor, but they have these impedance mashing papers that transform the kind of killer home.
And, of the NETWIRE, 1,200 on differential. And that's, gives you some nice features.
That, among other things, that gives you some ask, I'm gonna put on number resolution.
So if you put the next side, they have reasonable good enough for most applications. 13 people seconds, 50 and, you know, 70 s at 800, you can go to them.
And, our student Andrew Miller, who just graduated, he's, He did some experiments to combine these 3 space coupled filters that we had for DSock and to image, one to one, the light outside the chrystat, to a single mode fiber, and with that, was able to get, 72 was able to get, point
one counts per second. Dark count rates while having 72% system detection efficiency. So you combine that with a little j and you got this very nice, value of this, this each metric.
So this, this allows you to actually, so this is a really nice, compromise between, okay.
And you're like us also have some aspect of photons. And, so.
In the interest of time, we won't go into all the details, but essentially the height of the pulse can be continue information about how many photons came in.
So one of the things we've been doing is using multiple thresholds to discriminate so you can get time and number tagged photon arrivals.
And then the, we can also get, yeah. So you don't click.
You don't do it by the timing, but if you're a QP, I say different amounts of time to get to the left end and the right end.
We don't well we do that with used to checkers they have the different what we but we're not relying on that for this effect.
This effect essentially what you're doing, the fact that Joe, those are peanuts, The actual hotspot, the part of the detector that goes normal is really small is basically one square metal.
So if the wires 150 nanometers, it's like 155 or 50 nanometers.
So that means that if you have a 10 micron spot under 2 individual photons just about always produce 2 separate hotspots.
So now the resistance is not, you know, one kilohertz. And so you see a higher voltage at the end.
So the actual amplitude of the pulse at the end. So the actual amplitude of the pulse that comes out is correlated.
So what we do is we, you can measure the, arrival time at a low threshold and a high threshold.
And this can give you essentially the slope of the pulse. And that slope is, well correlated also with the, the, rival time.
In principle, you could also just, cut the threshold and do it only with amplitude, but there's, Basically, changes the time walk.
Well, there's something else. Yeah, actually, is a little different. I'm walk it's something that happens when the detectors are like at saturation. Yeah.
So in saturation, that if I, you know, had time with something I would talk about a little bit later.
We actually have a correction algorithm for the time block when the detectors are firing all the time, you know, you get a lot of little pulses out because the, not fully recovered.
And so they walk out from under your threshold. Because the current is not fully recovered. And so they walk out from under your threshold.
So what we've done, our student Andrew, he came up with a method where you, as you've done, our student Andrew, he came up with a method where you, and, came up with a method where you, do a calibration with a roadblock laser and you measure the timing offset kind of like a method where you do a calibration with a roadblock placer and you measure the timing
offset, kind of like in a constant fraction discriminator. And by doing that, that was part of the trick that allowed us to do this.
Then we can count that the big account while keeping the, time rise, the, below, 100 pico second.
So the time walk correction is actually critical to that. But this is a little different. Okay, I will go just the same.
We did some work to, even get these detectors, that's, we did some work to, even get these detectors, space qualified running, they wanna play qualified, we are at daughter with some radiation tests and lifelong tests and so, these detectors, for the principal.
So Justin, one slide I'll tell you about these, sort of. Peacock shapes, there's a couple little things that show up.
Yeah, so these are essentially a small arrays of detectors. So those other detectors I show you, they have all those nice features, but they didn't have high count rate, right?
Because it was all just one nano wire. So what we wanted to do was create a detector that was very similar to those.
Differential single pixels, but they made from the similar material. But instead of having a wire that, back and forth, the idea is that we would have 32 short straight wires.
And so they all get illuminated. So the idea is you have a spot that illuminates a bunch of different wires.
This is an actual histogram of light, eliminating the different wires. So you see the pitch and the fill factor of the wires kind of.
Nicely matches the mode distribution and capture about 90% of light. Overall this detector has about 78% system detection efficiency.
We were able to count at a 1.5 peak account per second count rate as the 2 DV point.
And, gets, keep the, time integer below a hundred picosecond at high rates, at low rates.
It's about 12 egal seconds. All the half max. So you can go.
To the next slides, real quick, we'll kind of skip over this. This this is showing that was showing the big account per second.
Maybe actually maybe go back to that. This is just showing that we get these, account for seconds. Rates.
So this is one wire and this is the whole array. And we have readout electronics also for Thomas Langer that can keep up with this.
So this has 120 inputs and count at 60 attacks per second. So in principle this TEC could support 4 of these detectors operating in one Priestat, account per second, which is the full 100 gigabit per second data pipeline, coming.
So it is actually not crazy. Well, think it's a little bit. To have more of these detectors in one price that to do a bill state measurement on a tenure hertz clock at gig account per second on each one.
So this is a capability that we're building up at JPL. We have a price app which we're building up to do this.
So if folks think this is a useful resource, it is possible to imagine taking something. In my busy like a Christ then it's anything special from the usual like soption that we're already using or besides the like.
Oh, like, readout, cabling and everything else. That's, that's kind of a big crowd.
I don't know that it needs to be quite as big as it actually is, but it is a big price.
It's not any, you know. See, you're like on computing standards, but, it's, got a to.
Sort of French. So essentially, yeah, it's, you need a lot of cables.
We are working on a project. So it's actually a DOE. Project with the, through the micro electronics, project to try to look at, very high density, interposers and cable assemblies to try to get to 1,000 meeting.
You know, anyway, is it possible to double count? Like one photon light up 2 of those.
Lines. I don't really know that interaction with the metal. Oh, right. Yes.
Okay, so if you put the wires too close together, but if these, if the design is, the projector is designed properly, it doesn't do that.
So we've measured like the cross top. We don't get, account on a neighboring wire.
But send one photon at the time. I'm not sure only one. Well, we do it with Passan.
Yeah, so what we do is if you send the, and then you look at. You know, correlated.
So if you just You know, with the time tiger, we record all the time back at once and then you can see that it's, you know, what's happening, you look for correlations between, and we don't see any, so it's.
Much less than 1%. Oh, okay, I should start talking, so that's fine. You can see if there's anything.
This is explaining the time walk correction that I was kind of explaining before. It works really well and allows us to get the more information in paper.
So and then we also you can Okay, okay, okay, okay. This is, yeah, we had done that characterization of a POP, yeah, of the technical.
This is a picture of that price that, since you asked this, this is my last slide.
I was just saying these are our kind of next steps and goals for this project or other projects. I was just saying these are our kind of next steps and goals for this project or other projects.
We wanna, we demonstrated that, detector. We have, a nice paper on that, but we, wanted to implement, you know, the full readout system here.
So we have everything is created in one price that we wanted to implement multiple once together in one price status I said to use as a resource.
And then, making the very high efficiency, you can take advantage of the photon number resolution on acquire.
We wanted to make them Go to have ultra high dynamic range. We think that they such a detector count at 10 gig accounts per second, which is kind of.
A crazy amount of optical power. It gives you, that has some actual very interesting applications, to have a detector with, Start.
And then of course we're interested in other exotic things like integrating SSPDs with nonlinear photonic platforms.
In the future, using some of these integers for, quantum state readouts. That's that's honestly What the prospects of getting something will work at or Calvin or Well, this is I presume like one or 2 Calviners.
Yeah, so these detectors all work at one Calvin. The, it's, it depends a lot on the weight length of a life.
So, at telecom. Yeah, so I think. It's it depends on you know what else you're willing to sort of sacrifice in terms of other you know performance in terms of gender and things like that some of the devices that we've been working with.
Like Hi TC, May be able to. To get there. And of course, you wanna comment on what do you think the prospects are?
I think, actually, the, the, Pelvin's actually a little bit stream, 2, Kelvin, already the progenics, and so there's actually been some recent developments.
Something off basic version of that. So that already is like. Good stuff. And I think that's very good.
Thanks.
But yeah, getting this kind of performance. So, but not be efficiently presumably. No, but, in terms of just like getting the mechanism of the detection to work.
It's sort of going from one to. It's 10 times harder. Basically. I see.
Well, how much? What? Over what dynamic range. Verified this.
So that's the case. So if you can come in 10 big accounts per second. How low can you go?
Right, well, you, you mean in a practical calm system. Or if you were to operate this detector, what's the Yeah, yeah, that's a great question.
So the, the detector itself in, you know, if you blank everything off and you're in a darker itself in, you know, if you blank everything off and you're in a dark environment, like in a dark matter experiment, gets, actually to one, count per day, which, we promised, many years
ago, in, in 2 days. Finally, we made it. So, yeah, so the, That's sort of the ultimate limit so far.
And, in practice, if you have a system where you're opening yourself up to a thermal black body.
It's a question of how well you do the filtering. But, Yeah, that's you know, we saw that we could get, you know, count rates down to the point one count per second.
Great wall with preygenic. Their band filters looking at a 300 Kelvin black body.
So if you You know, if you can count at 10 to the 10 photons per second and you can go down to 10 to the minus 5.
Principal, maybe that's 15. In practice, the reality is, you know, I guess my question is, Thank you.
Oh, how linear it is. Yeah, so I'm just making sure, well, the linearity.
So there are effects that come up because the detector is at dead time. So if I think that It's a question of how over how many orders of magnitude you need the response to be totally linear.
This is actually something that we look at because it's really relevant for some kinds of astronomy experiments where they want to have a really ultra stable defector.
So there's. Some tricks that you can play when you. Like if you have a hold off time where you delete counts that came too close to the last one to get away from that time effects.
I'm not giving you a number because we haven't actually, actually. Yeah, I mean, I think, it's a sidebar.
Yeah, Yeah, they're interesting things that you can do. So we've been talking to the missed folks, their applications in metrology where it's if you can measure a microwave power and you can measure at the single photon level then you can measure at the single photon level then you can actually connect.
You know, the metrology. There are things you can do. We did some experiments a few years ago with, where we used the detectors.
Optical sampling oscilloscope basically so they're actually applications in like semiconductor metrology and batonic metrology for the semiconductor industry, where that could be relevant.
Say you want to measure a modulator on a on a wafer without dicing it and and measuring it and you can actually in principle take a very faint light and do.
Anyway, I take it way too much. I don't mean to.
One
Okay, let me remove to the next thought Is it? And maybe we're gonna catch up during the day because we allow time for discussion and then we can come back to some of the questions from us.
And maybe we're gonna catch up during the day because we allow time for discussion and then we can we can come back to some of the questions for.
We'll stay here. So I'm Boris cooled. Really great to be.
It's my first time. And I made it. So. Yes.
That's okay.
Oh yeah, so I'm gonna talk to you about. So how we go from the, so the tech performance that I just talked about and how we've been applying, between Jake and Caltech, for these, quantum network.
So if you go to the next slide. So, a really close net team. So, so at Caltech obviously and we have as Matt pointed out, we have a new doctor.
And, we have, this is, Matt pointed out, we have a new doctor and they're just, and so we're very excited about that and actually a lot of the stuff I'll show here is Pioneer.
500. So we're very excited about that and actually a lot of the stuff I'll show here was pioneered by Andrew.
So we're really happy, that he was, for last 5 years. So yeah, contact us, out, who's going to be leading a lot of this.
So, and then of course everyone else that, told you about GPL. In particular, wanna highlight as well that we've got, a members from the obstacle con group.
So, they're gonna be working on this kind of free space quantum communication. So these kind of some additional members that you haven't seen from the Go to the next slide.
So not already showed you this, talking about these, the most important thing is that, you know, as you already mentioned, you have these 3 metrics combined together with efficiency.
And dot conference which we're all really good. You know, combining all that together, how we could actually do it for quantum networks.
And, starting from this. Performance of this. Andrew kind of started design. Novel entanglement sources which kind of just really optimized to detect themselves because most of the time the performance So we kind of like, that's our approach.
Where you make the best effect that we can and then we figure out, okay, how far push sources to match that performance.
So most important thing here is the at this one over a hundred max level, which is about 15.
So if you take one over that, that gives you kind of like the highest call credit. Communication system they can run.
So we went around 10 gigahertz, at times, told that's just available.
Sorry, let's see. Sorry, you take one over the. One over a hundred. So this is what most of the time you hear the full.
But that doesn't really characterize the performance. Very well. Oh, that that time will be, one of the tactics of, maybe 15 s.
Okay, so when, when you're taking one over, you're assuming you have a large array that you're not saturated.
One over for the clock group. Right, we don't have Yes, Okay, so that's the next slide.
Right. And the new things, to mention, this exact, the texture is directly deployable in a free space system.
And this is actually what 100 demonstrate was one of those first oh really impressive project he instrumented a free space couple system which to begin with it was actually 5 couple from the outside but it is fully free space but also now that we're talking in this project hybrid free space by the networks we actually have to know how to do that and the nice thing is, about hybrid, free space by the networks, we actually have to know how, to do that.
And the nice thing is, you can actually get low.com with the free space coupled system.
As opposed to file. It's just kind of comes from choose it for this one. So if I go to the next slide.
Yeah, and then, I also already mentioned this, but another thing that we have sort of the primary deliverable this project is those load just a single pixel that we're actually gonna be.
Deployment of contact, obviously, at, and aga. So that's actually kind of a.
You know, first of the work, but we are going to also have the bandwidth, and resources to be pushing these other, really exciting things.
One to see these, quantum networks take advantage of, so obviously the high conference, and the suppose the number solution is really exciting that's very normal thing for devices and we wanna see what we can do.
So anyone that's really, you know, cool, project that is,
That's like. Right, so if we now kinda dig in and, how, Andrew designed the source, So basically we, you know, we start backwards, right?
We know how to tackle 10 or 20 gigahertz at the clock, right? So we went ahead and designed the system that at 12.5 gigahertz corporate.
And so the way we do that is we start with the laser. It's actually, so 4 gigahertz.
So 4 gigahertz is the say, we create the time and qubit by, sending it from the front of the, you know, about up to, 7 75 or 70.
Then, the, so now we've got our qubit, which is, so this is type 0 as you can see and then we can split Alice in both photons.
With a course weightless. So the nice thing about this is that. We actually get all of these channels simultaneously.
So. You know, when I did this experiment, That's on off at moment.
We're just using one pair of SSPD, simple Pixel as it is, to analyze each channel individually one at the time.
But obviously if you wanted to run the system with much higher fruit but you would just multiply by the number of and in the future, it won't be happening in this project, but we can think of, project beyond this one.
We can actually start accessing all of these, with these cameras. Simple, so very excited.
That's the next slide. So this just kind of demonstrates the timing resolution of the, so as you can see, I told you that.
The corporate was followed by 5 years. That's what I mean by that is that the spacing between, you know, the early, the middle and the late pulses.
So, and the doctor can resolve this. Very easily. So what's the next slide?
This is actually kind of. Going through and showing the JSI of the source, after the, that's, channel.
So this means here, 68 kilohertz coincidences in that particular. Pairing with the channels.
And visibility is very good. you know, one thing that you actually, yeah, when you got to these really high cooperates, it's that, just become very small, very stable.
We don't know if there's no temperature stabilization. On those. And there's just a power supply in one of them.
Attracts the phase. Yes, what's the separation again? Hey, so as you can see here, this is the visibility versus, pump power.
So you're going from sort of like, 99% down to. You know, 19%.
Basically, what's whatever our source could provide. You can run it. Next slide. It's just a little overview of it.
Main results so if you actually take we didn't actually do the simultaneous direct it would just be to detect us at a time but if you so if you were to run page channel pass all at the same time Good to be looking at 3.5 mega coincidence.
Which is really orders. Else has been done for a time with distribution. If you do some sort of, you know, capital characterizations, you'd actually be looking at 2.5.
It's pretty megabit. Because next slide. Yeah, this is something I'm very interested in.
So, investigating this project. Now that we have this like culture, high clock rate system, instead of having that interferometer at the beginning to create that they wanna investigate a high dimensional time and distribution to see, how many, eBits you could have sort of, right?
So this is going to be a research topic within this project. Next slide. Yeah. Cool.
Right. So now I wanna get into, Hi, hybrid free space, fire networks that we're trying to.
It's deployed at, so we're going to essentially, the goal is to, you know, we know how to detect us.
We have. Sources. That we'd like to deploy networks and what we're going to put them into contact.
Our main laboratory which is this shadow the barge between Maria's group and Jacobs, they're located in, And then, we actually have 5 of us that obviously go all around Caltech and, we've recently sort of, connected off.
Just sort of network where we've got fibers that goes to call the call, which is the library.
And this whole is built in that's called that. And so we actually haven't find the link that goes over that.
And if you go to the top of this building, you can actually have a line of site that goes back to our.
At the bar so we're going to set up a sort of loop network where you'll start off in 5, you'll put a transmitter on the roof here and, and start closing the list.
So this is going to be really nice test, check the things that work nicely. At the moment this is a 15 Now, the reason that we're going down the road is because once you are on this roof and said if you look at the office of you actually see, one of the facilities of JPL.
So there is this kind of, facility called the Mesa, which is like, and we have sort of buildings that we have access to.
So that is actually going to be the, let's take the goal for the. Second and third, yeah, Okay.
Right, so this is, believe in all this experiment was actually done during COVID. It was, really, an impressive, job on Sean, so he literally managed to build this whole thing with 20% of his time.
So go in one day a week. All by itself, in a new library, never works before like screw things together.
And, actually, managed to make this work. It was really impressive and we're excited to pick it up.
But basically yeah he built these 2 like a receiver and transmitter and was able to sort of start testing in a laboratory type setting.
So this is kind of just showing some results where. You know, he has some, corrections, and he's able to correct for some, And it works, right?
So, the next slide.
Right, so this is what they will all look like, right? So. We this is the main campus of JPL and then there's this road that goes up hill and there's there's a thing called the Mesa this is where they do a parachute test.
So you'll go with that. They're not doing that moment. So, our plans for this year, for example, is to take some of these sources that Sean felt during COVID.
And and then one of the topical groups building. Here so a lot of these telescopes can be instrumented here and we're gonna do the link from, this building up to the Mesa.
Because they said we wanted to get some personnel up there. Because once we've done that, we can actually have a line.
Any of this is some demonstrations, that Alex Lowman did. From this building I believe.
He was actually able to take one of these telescopes and track the. Successfully. So we'll kind of have all the all the pieces.
What's the next slide? Yeah, these are kind of, this is the overview of what we're planning on doing.
So near one, we're gonna have this sort of test of the Mesa to check on campus.
Then in year 2, we're gonna start closing the link from JKL to Caltech and then we have free is where it all gets really exciting because one of these telescopes that JKL manages the mountains about 2 h away from Right now this is actually the offline.
Telescope for this cheap space. I was talking about, this is the state that they all don't need telescope.
Those are really designed for 50 50 contract spacecraft and we have a nice thing is if you point this telescope down you can actually do it across the valley demonstration.
So, you get free is what we want to do is basically, go across the value with the ski resort and then the summer you can just go there.
What, and then we can actually send it to the telescope and start doing.
Demonstrations with this.
And then, you know, on that you can actually stop building. Stop communication. Potentially dr. Oh, discussion.
That's basically a Yeah, we're just gonna, as far as project will be supporting this whole, network, Illinois by deploying these detectors and higher sources and JPL and Caltech, we're gonna start building on these hybrid free space.
Actually, so the source. The hybrid source. It's intended for like the swap bank.
It looks like the I can just like be over. It's like on my part, but I can do the swamp thing.
Like the Bell State. If you have all these DW, you have channels, you're gonna have to put each one into its own beam splitter.
That's right. Yep. Yeah, but I mean, the even just taking one channel, is already.
The highest rate source. It's a well. So, for this question, we'll just take one.
Got it. And what was the right? Yeah, the rate.
Yeah, you go, actually, you know, maybe it goes along with this.
Yeah, this one. Yeah. So one channel gives you 60,000. Okay.
Yes.
Just that point I think you can put the WDMs after the 50 to split or see one.
Multiple ones for each 10, maybe they will. So you're right. So you're talking about independent sources so you don't know that you're talking about independent sources so you don't know that you're gonna get channel you get channel 2 on this one.
It's only going to be when they both
So if you
Better if you only are trying to interfere. Into this channels themselves that will interfere with each other.
I think it is actually multiplex out afterwards. You're basically separating out those. In this case, the one of the reasons that we chose 12, 5, you get that's just because it's multiple of a hundred.
And obviously, if you look at the, set phase versus. All these in you know, the, constructive but destructive experience for each of the channel.
So you do, you only need one. We haven't actually shown that you can literally run the malls, but in principle, that's something.
Should be possible. And I think you're right. You then have to have a peep only fibers.
That's a dispersion. So that. Yeah, no, as long as the dispersion isn't.
Same on this bit. Yeah. Well, I'm saying if you're doing a belt, if you're trying to combine them.
Right. And they have to arrive simultaneously and you got your path lines so that they match for one of the colors.
Not obviously, Sure. That would be really interesting. No, that's, you all have to deal with all the, for the broadband sources.
No, I think to begin with, the easiest thing to do is just be, yeah, the being split on this side.
After the deal. So you have full control. And then, and then see what can be done.
And as I said, like in the future, it's not, within site. For this project but in the future you can replace all of this with the and the free space coupled camera.
Right. Of single phone on the, so that's what we're ultimately seeing. That's one of the vision.
Massively.
Yeah.
Okay, so, are we gonna project with your computer or did you send? Okay.
She says Hmm.
Yeah. Good luck.
And. I'm on Zoom. Yeah, that's what I mean. You're already connected.
Okay. And then we'll get to your file.
Okay, so.
Okay.
Okay, so I originally wasn't planning to present. Assign the Yes. This morning. Hopefully I can just correct that at a time.
I can do the introduction. Okay, so. Yeah, maybe talking about some work that we've done.
We are looking to do so we're mainly focused on the, distribution, teleportation, coexisting with plus the communications.
Steve P. So just as a. Overview of the topic. So if you have, say some fiber on network.
You might be able to scale it.
If you have quantum communications and classical communications, completely independent private infrastructure. Then this limits the available fiber links that you have between notes.
And then it can also get costly because, If some possible, traffic wants to be sent, they have to compete with that poster.
Keep that client dedicated. So if you could have both, and classical communications. Sharing the same fiber structure you can really be able to scale this or any fiber reduced costs.
That's there.
So the main limitation is, Spontaneous, Very good. It's one thing you're sharing is the So biggest issue because it has such a broadband spectrum.
So basically he has some very high power light. It'll interact with. Phone on inside of so the fiber and there's many vibrational modes and it creates this Complex spectrum.
Which is based on the frequency the turning between the classical pump here and then where you would place your relative to that.
And so. The 2 main strategies in client classical coexistence to reduce the impact of this noise.
Is one you can. You can kind of and understand the spectrum. So if you know where your classical pump is and you know have this noise distribution.
Is across other telecom for example you, you can. Hey, where to place your calling signal or classical signal to minimize the noise as much as possible.
So I've kinda plotted on this simulation where these different telecom, See, man, C, VAN, if you have both, the noise is pretty high, but if you offset the, the quantum or classical signal that have a very wide separation.
Oh, band and seep in significantly reduced. And then the other approach is to do narrow spectral temporal filming.
Generally, the ramen noise, from some independent classical channel will be generating these photons, but they have completely uncorrelated spectral and temporal properties relative to some, And so if you filter around in both frequency and time domain such as narrow coincidence.
Yeah, it's, you can reduce the.
So this is. 2 studies that we did to investigate what is the most optimal choice for either one of the classical wavelength.
Which is Jordan. I may give a little bit of the backdrop here. I think everyone knows that RAM and the amplifier that used to classical They have been used for decades.
Issue is that, Classically investigated. In the game. That's what the goal is that you It's some paper that you want to provide.
Again, that's it for the compound or LP or wherever you want.
There all kinds of people used to Make sure that this. So for this classical quantum coexistence, or We want to be completely different.
You wanna go as far away from that main, as possible. There is no nothing in the literature. So that's what Jordan has done.
Very meticulously. Measure. Various different combinations of.
Along the way discovered. Models of the fiber that don't For. That's the backdrop, I think.
Yes, that a lot of, Yeah, I, I would say that. These kinds of things haven't been investigated at all.
I mean, so. Using, IS used a long time ago, but we did find that. You know, most people use, for example, 1310.
Quantum or classical signal and no band but we wanna investigate Oh, the entire so We investigated calls.
Situations where it font signal was in the serial band such as system that, what would be the most optimal classical channel to do.
And then, at Northwestern, classical channel to do. And then, at Northwestern, to investigate, you know, what we need the optimal, which one, like, you had, say.
Yeah. Do you mind if I ask a question just, broadly when you're talking about co-existence, which, you know, are you most concerned about the scenario where You control the fiber and it's more classical content that you need to get your wants to calm down or it's doing class.
In a just pre brawl deployed fiber that has every kind of telecom pack. I would say both.
You know, there's been a lot of work, you know, for me, Oh, existing time synchronization systems and using some classical clocks.
Or you know, you'll have to say the state measurement results, basic notes.
So if you have independent fibers for that, right, that's gonna take both. Fiber.
Right. You might not have enough fibers to send it over. Independently. So, there's that, which is important.
And then a lot of my focus is very high data rate. Classical internet traffic so CEO band class but extremely high powers can you do stuff in that?
So kind of. Both. I guess the other point to make is that We really don't know how these systems are going to.
At this point, if you imagine there's some kind of a very complicated part of that work. And you know, as a full point you want to be able to do all kinds of possibilities in terms of whether that's different users may be requesting different kind of services
Annoying your fibers basically. One
Okay, so.
Yeah, so we investigated, both. These situations. So for example, time synchronization, and they use the 1310.
But when we measured the noise, then it's very far different regions. We tested a bunch of different O-band classical signals and measured the amount of noise across the.
And we see this, you know, multi mode shape here. You know, so this blue line is 1310.
And, Say, Fermi Live is 50. 36 nanometers. So if you look here, using 1310, is actually pretty high noise.
If you shifted it lower, so if you change it only 20 nanometers you can reduce the noise by, and then same kind of thing in the symmetric case.
If you have an, system, using less than 30 10 am. Significantly reduce the noise compared to the rest of the open.
So similarly, a lot of people do 30 10 quantum signals. But we should be showed that a few changes, you can really reduce.
Or if you use, no, then, the noise is pretty much, Good question.
Coming completely simultaneously, but you could imagine having some. Some, a little bit of a little bit of time sharing where the classical signal is it's just It's designed not to come at exactly the same time.
The question is whether or not What impact does this have on this? Cause I know you can get scattering in both directions.
And different propagation, and things like that. And so the question is, are you always, is this kind of the limit you always get because of the fact that things are going to different speeds anyway or if you if you were to slightly slightly time offset your quantum time off that question.
Well the one thing with that so to do time you know, without them you can overlapping it all.
You'd have to use the same way. This version, if you have very far, what I could reduce could be okay.
Yeah, Paul, so you're right. I mean, time multiplexing could be done. So we have another project on this quantum wrapper networking where we investigate some of I'm just wondering how close you can get before.
Is it only the detector time or you get multiple scatterings in which case. So there is something wrong on signal comes at all times in which because you can't do the tunnel.
Right, so that's double rally scatter because people use it. Okay, this is Rama, so I'm not sure if people have investigated double ramps, What can you get, on scattering and then that photon is then really scattered the other way.
That could be or the thing that I worry about is, you know, some kind of splicing or some detectors like that's like big story.
Okay. I don't know. A lot of times, So we investigated this right hand side.
Kind of real work situation. So, this fiber link connection is part of the, Okay.
The system or question where we sent both.
Some broadband open. Source. To to co propagate with this. Really high car, a webinar channel, so this would be kind of investigating.
Extremely hybrid, classical internet. Can you send? So, and, is about 48 kilometers.
And we, had tunable filters, 50, filters and basically. Standard process spectrum to investigate different.
And how they perform. Based on the noise that this generated so kind of confirm this this.
Spectrum, we're utilizing. You can achieve much more noise. Fine communication. As you increase the channeling the visibility.
So yeah, it's just in comparison. This result was the first. And, and, compare with, what's been done.
And we also, show. If you say multi-channel and thing. That 13 times.
Okay, so, recently, we've moved towards studying teleportation coexisting with classical communications and similar.
Idea of high rate classical communication, but it can be applied. So. This previously hadn't been done so people have only done single and taking the distribution and that.
Yeah, so we wanted to see, do teleportation. Over some fiber that's carrying.
Okay. So this is just one case that we came up with. There's a lot of different configurations.
That we had on some classical transmitter. That's not aplex to co propagate with some single phone, encoded, and this goes to Bell.
S. And then the classical signal bypasses the bell. And, it propagates on this fiber.
So the classical signal transmits this whole, And then. . Source one is multiplexed the code, counter propagate to And then you have teleportation.
So this is the, implementation that we did in our question. So we use an open teleportation system.
We're kind of guided by these noise. Is. So we send. 1290.
So we have and SVD. So, for both. the single photon.
So yeah, sorry, it's. One way, so. So it's like,
So yeah, we have a hair of it, single full time. Prepare some. And then, the, and we had a 5.4 kilometers, 4, 5.4 kilometers school, one.
So the total distance where coexistence. And the classical signal is a 400 gigabits per second possible signal.
What you said, so it came from starlight and was sent to our lab over that fiber length.
Where it was injected into this transportation system. And then route it back. So the classical link distances.
So the results for this, so we measure the amount of ramen noise, which is the amount of power that we injected into this fiber.
And so using narrowband filters, which one, allows us to do, but it also narrowly filled with around noise.
And using this optimized way like we found that we only had about a hundred pounds per second or no lot of power.
Which is Pretty high, so, or very low, counts, you know, for the amount of Sorry, how many actual?
Page for a second, you get terminal one. The noise at the high level.
So this, this is the amount of C band classical power we send in. So it's independent of the quantum system.
It's just the amount of noise that That.
And then so we did teleportation. It's very, it's QUEUE, but it's a measure.
We had 11 DVM of, And we got an average. F. And just quickly, so if you turn off the classical, I, actually, so I don't have.
Do you have a slide somewhere? I'm just curious. Yeah, so we actually measured so we increase the power, and measure, of the interference visibility and, entanglement.
And we really saw no real change. Would you change the possible follow? I mean, it yeah, it is really just because we have such low noise.
At 11 DVM, yeah. Yeah. I mean, there might be. Some slight change, you know.
I think all the longer distances that if you're, yeah, true coincidence, cause it's smaller.
Yeah. It's like dark basically How many true coincidence counts per second did you have for these measurements?
So for the teleportation we had about. Point 5 coincidences per second. So it's a 4, 12 month sentence.
So over the time we are pumping it pretty hard. So pretty high air generation rates, which will also, The case.
But yes, we had about point 5.
Sorry, this is with. Yeah, these are these are the fidelities with 11, so what do you also measure what it is if you don't know we didn't so we did the Yeah.
But yeah, we only just wondering how much impact this 11. And that's what governs the resulting fidelity, right?
So since we saw now We just did teleportation. The classical. I was in concept but uncorrelated background.
And you can estimate. Accidental coincidental. Okay. It really depends.
The amount of power really depends on the data rate, what kind of file. For example, backbone fiber.
Scenario, yeah, It's 400 gigahertz and see what they want us.
It's somewhere else. We just, like over 5, it comes to to have it just so propagated.
It's very very forward, they're correcting all kinds of things that are going on inside.
A lot of those are proprietary.
Okay, yeah, so real quickly, we are invested in this stuff. What if you increase? You know, Air generation rates.
And so this is just one example of the, 16. And This is with 18 VP.
You know, there might be some. Production here, but. Yeah, so, so we're continuing with the studies.
So. Yeah, other both investigating. So this will be done.
The number of possible situations could be There could be tons of different scenarios, right? You have 4 different fibers, possible signals, By direction, they could, have different classical wavelengths.
The noise properties. Different fiber lengths. So there's really a lot of different.
So, so some key parameters investigate similar to all other experiments. So for me, it's set up.
You know, some way it links them or noise, but All of this combination, and CNC, because a lot of classical.
I think it's important to understand. The capabilities there. And just generally compared our system a lot more noise.
So. We're able to investigate how well this. Alright, Yeah, how does, the, the impact of increasing fiber length, change things. So the ramen noise will increase.
Line signals will decrease. And then also how does, you know, optimal pair generation, for example, change as you, increase the noise, you know.
Okay, hi, you can imagine. 100,000 background counts per second. You know, how would that?
Exactly. So when you have much higher noise and lower transmission. It's generally not true that the most optimal fidelity is gonna occur at, you know, the lowest pair generation rates, which is.
Is the case in dark fibers, because you have to increase, you know, the, basically the signal to So.
Just as the So the plans for the work. Is, I think we'll just start with.
Adding one fiber into one of the arms. If that's the measurement one, adding in some WDMs to MOFF.
Some classical signal. And investigate and and then kind of build up by adding . So we'll start it out with some continuous way, place a source for example, and just kinda see as a function of power, what kind of capabilities you have.
And from that you can kind of extrapolate, say if you had some. 1, 2 times supernexation or whatever.
Based on the amount of power that you can tolerate. What kind of things? 2 good experiments that we could try, so.
Having 2 parameters, a screen fiber, the, the, for me, length for about 65 school fiber.
It's like that for me. And then also, yeah, decide What kind of classical bit links?
Or.
Okay. Another difference of course would be for me experiments are all. Yeah, so.
There. It's hard to imagine. Yeah. I think generally, I'm a noise one impact on both too differently.
Assuming, assuming the noise is, friendly, distributed, first, for your kind of thing, I suppose.
One time versus the other then you could kinda have some of your effect going on. But if the noise, can be a white noise.
Thanks.
Yes. Okay. So as we have Andrew, last one before lunch.
Perfect. We don't want
But some of them are. Yes. Call. Yeah.
Okay.
See you.
Okay. Alright, so my name is Andrew. I'm a new postdoc here at F.
And I think these, are actually kind of a central place for a lot of the different things we're all working on the room are all working on the room are being tested so I guess there's someone in the room that's my expert and everything will get to say.
Well, the fair questions of details to people in the room, but hopefully we'll get a nice summary of things.
Okay, so I'll start by talking about the architecture and the geography here. We're right now in the, and I have that as a blue star on the map here.
A lot of the passport network experiments that have been done from you. That's about 2 kilometers away from us on the ring.
We also have our connection to Argon. Jordan mentioned coexistence before a picosecond synchronization experiments for the, that's a much longer life.
The 59 kilometers. And I think in the new year we're starting to set up a new lab at IRC to be able to kind of do quantum communication protocols and different.
Okay.
Alright, we've talked a lot about entanglement slopping and I think most people know it, but a quick motivation for why of all the quantum communication protocols we could be doing okay with this one.
I think the most obvious are the one that comes to me the most is repeaters of an application that we care about.
Classical telecom if you want to amplify your light to extend how far you can send it. It's simple to copy the log and send many copies altogether in your output.
But in quantum mechanics, we have the note cloning theorem. It stops us from being able to do that so we can't just copy and then paste our bike.
To give you the simplification process, but people have figured out that. If you have, quantum memories, which people on the room seem to be familiar with.
And you can start a live long enough for this interaction to happen. You can imagine many quantum entanglement swapping.
Procedures all linked together and if you can wait long enough for all the other state measurement Outcomes to be sent to the different parties with multiple rounds of entanglement swap and you could transfer the correlations from A all the way to Z.
So this allows us to think of longer network. On the metropolitan scale. And although we don't have the memories yet to be able to do this.
We talked about this network should be able to do many things that are going to be available in the future depending on what different users need.
So. We continue to be ready for that day.
And some quick theory on, I'm imagine you're out of an, actually entangled state or a bell state of 2 different EPR sources and we can label the photons 1, 2, 3, 4.
When you write the full 4 photon state, you have a tensor product of these 2 states. And I was just mentioned in, we haven't, time been entanglement.
So whether a photon arrives early or late determines its state. You can rearrange this state, to look like these 4 terms.
Where you can see we grouped such that a Bell State measurement on the 2 middle photons 2 and 3.
Would you have the same bell state among the photons one and 4? So transferring the correlations of the original pairs to the adjacent tips.
And I also said this morning, Bell State measurements are accomplished with beam splitters. So we need to make sure that you photons arrive in the same time and space out of each foot.
So this has been done. It for me love just the summer before I start working. In the C 0 building, we have 2 a single photon sources, 5 resources here.
And we've got one opus, that's an SPDs and in the corner that you can't see there.
And I guess important that out here is that these 2 internal photon sources come from one laser. So we have one laser that's split up into 2.
I'm trying to copy this system and build another set of entangled photon sources at this building that we're in now.
I guess a big focus of the first test will be make sure we can do this with 2 different lasers because surely in future applications the lasers will need different labs.
We need to make sure this works.
Okay. So back to that D 0 set up, kind of from a top down perspective. Here's our 1536 now.
I see w laser that's split up into 2. We have an AWG that controls intensity modulators to pulse the life.
And, just like was talked about earlier today, there's SHG and then down conversion that goes from blue back to 1536.
And because it's both, we have single photons in the early and like time. And if you think about these 2 rectangles and a single photon sources, that's like the 5 plus one and 2 state and 3 and 4 state I mentioned on the previous slide.
We have a variable delay line and make sure that the 2 photons from each path arrive at the same time.
And this allows us to do a projective measurement on a 2 photon fell state. Which would give you photons one and 4, correlation and to make sure we've done this properly.
We need 4 full points and accounts between all 4 of the detectives.
So, these weren't taken by me before I started working. Yeah, they did. There are relevant results in the swapping protocol.
First of all, if you look at the home of Mandela, as you turn that variable delay line in the past slide, we can start to see the coincidences.
Diminishing as we expect. And also, I didn't show on the last slide, but it was talked.
When I think it was, I was talking about that try pattern for early and then early plus late and late for 10 min.
We have Mocksander interferometers that we can use to measured in a superposition basis.
So, that's on top of each other so that we don't know what we're measuring earlier.
Right. Those interferometers have a voltage that you can apply to change the phase on only one of the 2 arms.
In a, which allows you to change the phase of the light and then change. And every 2 of those, the maximum and the minimum kind of stand as we expect here.
And I wanted to bring up the side, if they're not my results, but I did want to bring up that, this is kind of the easiest case scenario.
One laser, 2 source, in the same table, and the 4 full coincense counts are getting over 3 h is around the 50 mark.
So be able to do this long term or, you know, between 2 buildings in Permulo campus.
We've got a few photons to work with. And I mentioned this because that motivates these high rate and gentleman sources that Caltech has been talking about.
So we will be doing things on campus. With the idea that eventually you can change the spacing of the time.
Then to the pulse rate of the rays, the pulse rate of the modulators to then kind of plug in these high rate sources and hierarch detectors.
So all the same physics works as long as your system is modular enough to be able to replace the things with the upgraded versions.
So that was 80 p per second dead separation. For as mentioned, it's hopefully in our future.
And for now, we're at 300, and 60 per second. So everything's down a little bit slower and further apart.
And then someday we'll squeeze everything together to be able to go longer distance. Oh, good question.
Yeah, I'm sorry. You said you were at what now? 3 63 60.
Yeah between early and next. Yes, does that mean that your and you go back. That mean your accounts are gonna go to 40 every hour and set up 40 over 3 h.
Yes. Yeah. Okay. Well, then for one source.
Let me know. If you're adding more, But. That's only if you're looking at the in each of those bits, but the probability per attempt is not changing.
You're just.
Oh, you might be right. Cause you can't, you're not able to interfere all 3 of these at all 3, right?
It's only, this one goes, this, this, this, this, Oh, pulls program.
This is not meant to be a criticism of the field that we can't. I can't do anything with 40 accounts.
I mean, the question is, is there, do we collectively have a way to get something that's useful?
If you want to do like distributed quantum computing where you want to do like distributed quantum computing where you have to have 1,000 accounts a second.
There's another kid that we're getting coming here. I believe it's from the You know, it's an interferometer.
So each harm we're missing about like 3 dB. Okay, the success rate after you analyze it.
But the actual that need like if you don't need to verify that you swap correctly then you would not have that the loss.
And that's something that, so are you, because you remember a number of, but I think, we found a new version of the interferometer that can reduce that to like every point 3 your point 4.
So it's like, we're getting a couple of TP pair output of from there.
So that's, and that anything adds up like, it will be like, we'll gain like up to 8.
TVs, so factor like an extra 10, close to that. They're also looking at much lower less filters.
I wasn't here for this experiment, but I've heard that the filters that were using were Greg filters and they were losing most of the light going in and out of those.
Just respect really narrow which part of the photons I'm looking at. I think that there have been tests of Ealon filters.
More work in the coming months to lower the last. In. In addition, yes, it scales as you say, but maybe we'll get that tabletop version better.
We'll probably get that tabletop version better. It will probably won't get to the. Yes, it scales as you say, but maybe we will get that tabletop version better.
And we'll probably won't get 10 to 100, I think that's kind of what we're shooting for.
Yes, you can. With your interferometer and you said, I don't think you get to count it twice because the photons either going here or it's going here, you know, it doesn't experience both of those losses.
You get accounted for this interferometer and for this interferometer. You don't get, yeah, yeah, yeah, sorry.
So maybe it's like, yes, so 3, in each, it's about 6. Yeah, yeah, you're saying it's not times.
Yeah, yeah, you're saying it's not time for the long time. Alright, move on.
I'm here for a moment. The swapping between the 2, the 2, sources have happened.
So that's like our initial attempt at this. We're now going to be stopping between 2 sources of FCC.
It's upstairs on the third floor. I can show people there. I don't know how pack this schedule is, but if you're seeing at some point in the downtime.
You wanna see it? And then obviously when you can do it in both of these buildings and now you can do it 2 separate lasers or 2,024, to be able to do swapping across campus.
Leading to the point of the talk, which was Argon swapping. When the higher rate sources come in in the higher rate detectors or the lower jitter detectors come in.
That range would be extended to our.
Yeah, I've got some pictures here. That's awesome to see now. I only have a single, but we've done our best to copy.
Good parts of the source in D 0. As you know, we don't have an AWG anymore.
Instead, we have a kick system, the quantum instrumentation control kit, and Gustavo is going to be talking about this later this afternoon.
But we have people that, that make these systems that. Can help us pulse our light and then in the future they'll be used for feed forward controls or any kind of feedback and, that happen on the table.
All kind of custom made.
Also wanted to show you what my day to day is like since I got here this is incredible this Caltech software is so much better than I think most quantumics left it to use.
This is 4 channels, so a single photon source. Each of the photons goes into a bob center in a phone and we look at the 4 output ports.
So those are these 4 channels. You have 6.5 nanoseconds between qubits.
And I mentioned 3 60 picoseconds between early and late. And there's that driving pattern again that we saw this morning where that knocks out there in a phone or can mix your Tuesday so that you don't know whether it's coming from early or late time bit.
This one's kind of software is incredible in my opinion because you can tune the windows individually. So red, yellow, green, I have to the 3.
You can use like up to thousands of qubits at once where you can take statistics from successive qubits in the train to compare coincidences from success of qubits in the train to compare coincidences and coincidence this can be counted between any kind of different windows.
So. Maybe that's standard for people here, but Coming from Canada, this was a big video.
We have scripts that have been using past experiments that can analyze this. So this all being set up and And finally, these are the disabilities and channel visibility you get from during the Voltage.
So, what we see, the basis visibility, basically how well can I tell, for instance, counts from early early versus early late if we shouldn't see any instance comes from.
We see it pretty much a hundred percent. I would have to count longer to get dozen places. And then in the x-axis, we're turning, tuning that in a parameter voltage.
We get nice interference French patterns but we're seeing only about an 80% visibility so I think we need to be working on that.
Okay.
Oh, our friends at Argonne also sent me some slides to present here. We have, Argon kinda simultaneously, they're working on a quantum network with the start apology, so they have 5 different nodes here.
And I think it's this note in the bottom right corner that's connected to. So the long 5 or comes in here.
They, they have Commercially available on single phone phone, which is what we're seeing all morning is cascaded SHG and SPVC sources.
They have optical switches on campus that are 16 input and output channels which allow them to change which direction the photons are going.
And there are 2 detectors from, I think, similar to the detectors we have at the D 0 building that 85% efficiency.
And it's been alluded to already, but there have been timing and synchronization experiments between Fermi and Argonne already.
And the user, I can consider on our timing guys. So when we do this entanglement swapping experiment.
In the future. There may be new controls we need for that and a lot of this synchronization will happen because the work done at Argonne.
Lastly, as a summary there, preparing, to be a Bob node or to be one of the 2 notes that receives an entangled photon at the end.
And changing the synchronization needed and also just like our love looking at getting lower to their SSDs.
So when we increase the rates of these things. Okay, I think my last slide. There's a coexistence was just discussed very soon.
We'll be working on coexistence experiments. I think at the D 0 building because we already have the 2 sources set up.
I mentioned there was different combinations of channels you could put your classical light in. There's a lot of fibers going on.
So we'll be playing with which experiment we want to look at. And, so this already a few times, but the long role being slopping between, And I think that kind of includes most people in the room and the topic.
But I didn't talk about your side. I apologize. I probably don't understand. Thanks for the time guys and let's see some lunch.
Hello. So before you guys, go for lunch, first of all, I mean, I'm sure Christian, welcome you.
Point of view, I would like to welcome you from the point of view of the laboratory. Bye, good, PANGURIES.
I am the Special Lab Director for And, and also I am, I'm an addict, I've been doing this kind of stuff for a while, I've been the PI.
So, but you know, off with the hold and on renew. So that's one message.
You know, good luck. The other thing is a trivial thing, you know, it's, great.
Everybody's together. So on the way out for lunch, let's take a group fixture.
There's a picture of, you know, as you are entering the building, so let's gather underneath.
You know, whatever you might, you might not like, you know, whatever you might, you might not like payment, but most of us.
Good. I like the picture under respect. Hard to find someone who doesn't like. There are people.
And the third thing, it is also the reality. We should take a account and who is going for dinner tonight because I have one request.
Sorry. She died, I were late coming in. There are a lot of people in the room I recognize because it worked with them before, but there are a lot of people I don't.