Perturbative approach to non-Markovian stochastic Schrödinger equations

In this paper we present a perturbative procedure that allows one to numerically solve diffusive non-Markovian stochastic Schrödinger equations, for a wide range of memory functions. To illustrate this procedure numerical results are presented for a classically driven two-level atom immersed in an environment with a simple memory function. It is observed that as the order of the perturbation is increased the numerical results for the ensemble average state ρ_red(t) approach the exact reduced state found via Imamog¯lu^′s enlarged system method [Phys. Rev. A 50, 3650 (1994)].