  Quantum computing raises the possibility of solving a variety of problems in
physics that are presently intractable. A number of such problems involves the
physics of systems in or near thermal equilibrium. There are two main ways to
compute thermal expectation values on a quantum computer: construct a thermal
state that reproduces thermal expectation values, or sample various energy
eigenstates from a Boltzmann distribution of a given temperature. In this paper
we address the second approach and propose an algorithm that uses active
cooling to produce the distribution. While this algorithm is quite general and
applicable to a wide variety of systems, it was developed with the specific
intention of simulating thermal configurations of non-Abelian gauge theories
such as QCD, which would allow the study of quark-gluon plasma created in
heavy-ion collisions.
