Momentum-resolved radio-frequency spectroscopy of ultracold atomic Fermi gases in a spin-orbit coupled lattice

TL;DR

This paper theoretically demonstrates that momentum-resolved radio-frequency spectroscopy can effectively measure the band structure and single-particle states of a spin-orbit coupled ultracold Fermi gas in a lattice, considering realistic experimental conditions.

Contribution

It provides a theoretical framework for using rf spectroscopy to probe band structures in spin-orbit coupled Fermi gases in optical lattices, guiding future experiments.

Findings

Rf spectroscopy can resolve band structures in spin-orbit coupled lattices.

Temperature and trap effects are significant in measurements.

Predictions are made for future experiments with 40K atoms.

Abstract

We investigate theoretically momentum-resolved radio-frequency (rf) spectroscopy of a noninteracting atomic Fermi gas in a spin-orbit coupled lattice. This lattice configuration has been recently created at MIT [Cheuk et al., arXiv:1205.3483] for 6Li atoms, by coupling the two hyperfine spin-states with a pair of Raman laser beams and additional rf coupling. Here, we show that momentum-resolved rf spectroscopy can measure single-particle energies and eigenstates and therefore resolve the band structure of the spin-orbit coupled lattice. In our calculations, we take into account the effects of temperatures and harmonic traps. Our predictions are to be confronted with future experiments on spin-orbit coupled Fermi gases of 40K atoms in a lattice potential.