Fully quantum simulation of laser cooling of multilevel atoms in three dimensions

In the simulation and analysis of atom-laser interactions, and in particular laser cooling processes for systems containing multiple energy levels, we have typically relied on semiclassical approximations and analytic solutions. Recently, developments in computational speed and power have allowed us to study fully quantum numeric results in more complex systems than previously possible. This maintains the ability to study the effects of superpositions and atomic coherences, important at low temperatures. We present a fully quantum Monte Carlo wavefunction simulation method that allows us to model the wave function in three dimensions, and in limited systems with arbitrary non-degenerate energy manifolds. We employ this technique to examine multiple atomic systems in three dimensions, including doppler, polarization gradient, and grey molasses cooling.  Our work is motivated by the desire to understand laser cooling in complex systems such as molecules that possess many internal degrees of freedom.