31 July 2023 to 4 August 2023
America/Chicago timezone

Infrared Phases of 2d QCD from Qubit Regularization

31 Jul 2023, 16:20
20m
One West (WH1W)

One West

WH1W

Parallel Talk Theoretical Developments

Speaker

Hanqing Liu (Los Alamos National Laboratory)

Description

Qubit regularization provides a framework for studying gauge theories through finite-dimensional local Hilbert spaces, presenting opportunities for digital quantum simulations. In this talk, we investigate the IR phases of 2d QCD with the $\mathrm{SU}(N)$ gauge group via qubit regularization. In the continuum, a 2d $\mathrm{SU}(N)$ gauge theory coupled to a single flavor of fundamental massless Dirac fermions can be bosonized into an $\mathrm{SO}(2N)_1/\mathrm{SU}(N)_1$ Wess-Zumino-Witten (WZW) model or a compact boson. On the lattice, utilizing a strong-coupling expansion of the qubit-regularized Kogut-Susskind Hamiltonian with the assistance of a generalized Hubbard coupling, we demonstrate that the continuum physics can be reproduced by an XXZ spin chain, together with a gapped phase. We also show the existence of a confinement/deconfinement (screening) transition. These arguments are verified numerically in the $\mathrm{SU}(2)$ case using the tensor network approach. Our numerical results reveal that the lattice model has a central charge of 1, and its spectrum can be understood as the $\mathrm{SU}(2)_1$ WZW model perturbed by a tiny marginally irrelevant operator, which can be tuned away by the Hubbard coupling. The confinement/deconfinement transition is also verified numerically by measuring the string tensions.

Topical area Theoretical Developments

Primary author

Hanqing Liu (Los Alamos National Laboratory)

Co-authors

Tanmoy Bhattacharya (Los Alamos National Laboratory) Shailesh Chandrasekharan (Duke University)

Presentation materials