Quantum simulation of real-time dynamics in Gauge Theories

A quantum simulator for a U(1) gauge theory coupled to fermionic
matter (Schwinger model) is constructed using quantum links, which
realize continuous gauge symmetry with discrete quantum variables.  At
low energies, quantum link models with staggered fermions emerge from
a Hubbard-type model which can be quantum simulated using a Fermi-Bose
mixture of ultra-cold atoms in an optical lattice. This allows us to
investigate string breaking as well as the real-time evolution after a
quench in gauge theories, which are inaccessible to classical
simulation methods. Although the model is simple example in
(1+1)-dimensions, there is, in principle, no problem in extending the
method outlined here to higher dimensions and non-Abelian gauge
theories.