Driven-dissipative quantum Monte Carlo method for open quantum systems

摘要

We develop a real-time full configuration-interaction quantum Monte Carlo approach to model drivendissipative open quantum systemswith Markovian system-bath coupling. Themethod enables stochastic sampling of the Liouville-von Neumann time evolution of the density matrix thanks to a massively parallel algorithm, thus providing estimates of observables on the nonequilibrium steady state. We present the underlying theory and introduce an initiator technique and importance sampling to reduce the statistical error. Finally, we demonstrate the efficiency of our approach by applying it to the driven-dissipative two-dimensional XYZ spin- 1/2 model on a lattice.