Spin distillation cooling of ultracold Bose gases

The principles of spin distillation cooling were initially demonstrated experimentally for a chromium dipolar gas [B. Naylor et al., PRL 115, 243002 (2015)]. We have simulated this using a classical field approach, and find two very different cooling mechanisms in 52 Cr and 23 Na atoms. Through numerical simulations, we demonstrate that the spin distillation cycle can be repeated several times, each time resulting in a significant additional reduction of the thermal atom fraction. Threshold values of magnetic field and limitations on the achievable temperature are also identified.