Artificial Quantum Thermal Bath

In this talk, we present a theory for engineering the temperature of a quantum system different from its ambient temperature, that is basically an analog version of the quantum metropolis algorithm. We define criteria for an engineered quantum bath that, when couples to a quantum system with Hamiltonian $H$, drives the system to the equilibrium state $\frac{e^{-H/T}}{{{\rm{Tr}}}(e^{-H/T})}$ with a tunable parameter $T$. For a system of superconducting qubits, we propose a circuit-QED approximate realization of such an engineered thermal bath consisting of driven lossy resonators. We consider an artificial thermal bath as a simulator for many-body physics or a controllable temperature knob for a hybrid quantum-thermal annealer.