In a collaboration with experimentalists in Paris (Cold atoms group, LPL) we studied the non-equilibrium dynamics of a gas of ultra-cold Chromium atoms trapped in an optical lattice. In particular we studied the time-dependent build-up of quantum entanglement due to dipolar interactions and found new insight into the systems’ approach to equilibrium. This work has now been published in Nature Communications: Nature Communications 10, 1714 (2019).
To simulate the experiment we had to develop a new numerical tool: the generalized discrete truncated Wigner approximation (GDTWA). This semi-classical phase-space approach extends the well-known truncated Wigner approximation to discrete lattice spin-models with arbitrary local spins S>1/2. The method works for very large system sizes and arbitrary dimensions, and we find it to be remarkably precise in predicting out-of-equilibrium physics. Now, we introduce this method in a new pre-print, available here: arXiv:1905:08782.