Direct production of fermionic superfluids in a cavity-enhanced optical dipole trap

TL;DR

This paper demonstrates the creation of fermionic superfluids using a cavity-enhanced optical dipole trap, enabling efficient cooling and Bose-Einstein condensation with low laser power and minimal lattice effects.

Contribution

It introduces a novel cavity-based trapping method that simplifies ultracold fermion production and reduces power requirements compared to traditional traps.

Findings

Successful production of $^6$Li superfluids in a cavity trap.

Near-complete cancellation of lattice structure along the cavity axis.

Efficient formation of molecular Bose-Einstein condensates.

Abstract

We present the production of quantum degenerate, superfluid gases of $^6$Li through direct evaporative cooling in a cavity-enhanced optical dipole trap. The entire evaporative cooling process is performed in a trap created by the TEM$_{00}$ mode of a Fabry-P\'erot cavity, simultaneously driven on several successive longitudinal modes. This leads to near-complete cancellation of the inherent lattice structure along the axial direction of the cavity, as evidenced by the observation of long-lived dipole oscillations of the atomic cloud. We demonstrate the production of molecular Bose-Einstein condensates upon adiabatic conversion of a unitary Fermi gas evaporatively cooled in this trap. The lifetime and heating in the cavity trap are similar to those in a running wave dipole trap. Our system enables the optical production of ultracold samples using a total trap-laser power below $1$ W, leveraging the benefits of optical resonators as dipole traps in quantum gas research while maintaining a simple resonator design and minimizing additional experimental complexity.