How a trapped-ion quantum computer can prepare the finite-temperature, finite-density thermal states of non-Abelian gauge theories with two (SU(2)) and three (SU(3)) colors in one spatial dimension, sidestepping the sign problem that blocks classical Monte Carlo at nonzero chemical potential. The construction minimizes free energy variationally, uses the ions' motional modes as ancillae to build the mixed thermal distribution, and enforces color neutrality through group-theoretic charge-singlet measurements. Studying this gives a concrete example of mapping a lattice gauge theory onto quantum hardware to reconstruct a phase diagram.
This experiment performs the first quantum simulation of quantum chromodynamics (QCD) thermal states at finite temperature and finite matter density, for both SU(2) (two-color) and SU(3) (three-color…