Cooling schemes for two-component fermions in layered optical lattices

TL;DR

This paper evaluates a proposed cooling scheme for two-component fermions in layered optical lattices, finds it ineffective, and introduces an alternative method that successfully reduces the system's temperature.

Contribution

The authors demonstrate the failure of a previous cooling scheme and propose a new method that effectively lowers the temperature of fermionic layers.

Findings

The original scheme does not effectively cool two-component fermions.

The new scheme reduces the temperature by approximately 50%.

Both full-Hilbert-space and matrix-product-state methods support these results.

Abstract

Recently, a cooling scheme for ultracold atoms in a bilayer optical lattice has been proposed [A. Kantian et al., arXiv:1609.03579]. In their scheme, the energy offset between the two layers is increased dynamically such that the entropy of one layer is transferred to the other layer. Using the full-Hilbert-space approach, we compute cooling dynamics subjected to the scheme in order to show that their scheme fails to cool down two-component fermions. We develop an alternative cooling scheme for two-component fermions, in which the spin-exchange interaction of one layer is significantly reduced. Using both full-Hilbert-space and matrix-product-state approaches, we find that our scheme can decrease the temperature of the other layer by roughly half.