Low-noise optical lattices for ultracold $^6$Li

TL;DR

This paper reports the creation of stable, low-noise optical lattices for ultracold fermionic $^6$Li atoms, enabling long-term trapping and precise measurement of atomic populations with minimal heating, advancing quantum gas microscopy.

Contribution

It introduces a method for stable, long-term trapping of $^6$Li in low-noise optical lattices with detailed lifetime and heating rate measurements.

Findings

Ground state lifetime of 71 seconds at low heating rates

Radial ground state lifetimes exceeding 1.6 million recoil times

Ability to measure population distribution among lowest three bands

Abstract

We demonstrate stable, long-term trapping of fermionic $^6$Li atoms in an optical lattice with MHz trap frequencies for use in a quantum gas microscope. Adiabatic release from the optical lattice in the object plane of a high-numerical-aperture imaging system allows a measurement of the population distribution among the lowest three bands in both radial directions with atom numbers as low as $7\times 10^2$. We measure exponential ground band heating rates as low as 0.014(1) s$^{-1}$ corresponding to a radial ground state $1/e$ lifetime of 71(5) s, fundamentally limited by scattering of lattice photons. For all lattice depths above 2 recoil, we find radial ground state lifetimes $\ge 1.6 \times 10^6$ recoil times.