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

by Tabea Bühler, Timo Zwettler, Gaia Bolognini, Aurélien Fabre, Victor Helson, Giulia Del Pace, Jean-Philippe Brantut

Submission summary

Authors (as registered SciPost users):

Tabea Bühler

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 is similar to that of 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.

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