Number-phase Wigner representation for scalable stochastic simulations of controlled quantum systems

Simulation of conditional master equations for many-body systems is important for state estimation and control of large quantum systems. Many-body conditional master equations have been simulated recently with stochastic methods, but the convergence time was restricted by the use of representations based on coherent states. We demonstrate that applying a stochastic method based on the number-phase Wigner (NPW) representation can converge over an order of magnitude longer than it´s coherent equivalent. This technique can provide a drastic improvement in the convergence of simulations of controlled many-body quantum systems.