Magnetic field dependence of Raman coupling in Alkali atoms

TL;DR

This paper calculates how magnetic fields affect Raman transition rates in alkali atoms, revealing that rates decrease with field strength and highlighting implications for combining Raman processes with Feshbach resonances.

Contribution

It provides the first detailed calculation of magnetic field dependence of Raman coupling rates in alkali atoms, including the notable suppression in $^6$Li.

Findings

Raman rates decrease with increasing magnetic field due to spin decoupling.

At typical Feshbach resonance fields, Raman rates remain comparable to zero-field values.

$^6$Li$ shows a sevenfold suppression in Raman coupling compared to other alkali atoms.

Abstract

We calculate the magnetic field dependence of Rabi rates for two-photon optical Raman processes in alkali atoms. Due to a decoupling of the nuclear and electronic spins, these rates fall with increasing field. At the typical magnetic fields of alkali atom Feshbach resonances (B\sim 200G-1200G), the Raman rates have the same order of magnitude as their zero field values, suggesting one can combine Raman-induced gauge fields/spin-orbital coupling with strong Feshbach-induced interactions. The exception is $^6$Li, where there is a factor of 7 suppression in the Raman coupling, compared to its already small zero-field value.