Spin distillation cooling of ultracold Bose gases

Konwersatorium wydziałowe (online)

Dnia 2021-05-11 o godzinie 13:15 odbędzie się wykład (seminarium odbędzie się „online” z wykorzystaniem platformy ZOOM), na którym dr hab. Piotr Deuar z Instytutu Fizyki PAN Warszawa, wygłosi wykład pt:

“Spin distillation cooling of ultracold Bose gases"

Serdecznie zapraszamy

Andrzej Maziewski

Jerzy Przeszowski

“Spin distillation cooling of ultracold Bose gases"
Piotr Deuar
Instytut Fizyki PAN Warszawa

In the ultracold gases field, evaporative cooling down to nanoKelvin temperatures is routinely achieved in order to obtain Bose-Einstein condensates. However for some this is not enough, and the search for new and/or better cooling techniques is an active field of research. One promising approach that applies to gases with a nonzero quasi-spin (i.e. several allowable magnetic states of the atoms) is spin distillation cooling. This relies on shifting the energetic atoms to a different magnetic state which is later removed, leaving a cooler remnant. The principles of spin distillation cooling were initially demonstrated experimentally for a chromium dipolar gas in 2015. Our Białystok-Warsaw team has numerically simulated such a cooling process using a classical field approach, and we find two interestingly different cooling mechanisms in 52 Cr and 23 Na atoms. We have demonstrated that the spin distillation cycle can be repeated several times, each time resulting in a significant additional reduction of the thermal atom fraction. I will talk about the background of the topic, and about some details of the cooling process that our simulations revealed. (P.D.)