Preparing a highly degenerate Fermi gas in an optical lattice

TL;DR

This paper presents a method to prepare ultra-cold, highly degenerate Fermi gases in optical lattices with uniform filling, enabling advanced studies of quantum many-body physics and quantum information processing.

Contribution

The authors introduce a novel adiabatic loading and filtering technique using a non-harmonic trap to achieve extremely low temperatures in fermionic gases within optical lattices.

Findings

Achieves temperatures around 10^{-3} of the Fermi temperature.

Enables exploration of the Fermi-Hubbard model at low temperatures.

Facilitates high-fidelity quantum register initialization.

Abstract

We propose a method to prepare a sample of fermionic atoms in a three-dimensional (3D) optical lattice at unprecedentedly low temperatures and uniform filling factors. The process involves adiabatic loading of atoms into multiple energy bands of an optical lattice followed by a filtering stage whereby atoms from all but the ground band are removed. Of critical importance is the use of a non-harmonic trapping potential, taken here to be the radial profile of a high-order Laguerre-Gaussian laser beam, to provide external confinement for the atoms. For realistic experimental parameters, this procedure should produce samples with temperatures $\sim10^{-3}$ of the Fermi temperature. This would allow the investigation of the low-temperature phase diagram of the Fermi-Hubbard model as well as the initialization of a high-fidelity quantum register.