Combination of a magnetic Feshbach resonance and an optical bound-to-bound transition

TL;DR

This paper demonstrates a method to control Feshbach resonances using laser light near an optical transition, reducing atom loss and enabling precise spectroscopy in an optical lattice.

Contribution

It introduces a novel technique combining magnetic Feshbach resonance tuning with optical bound-to-bound transitions, including a detailed theoretical model and high-resolution spectroscopy.

Findings

Reduced light-induced atom-loss rate by an order of magnitude

Successful operation in large detuning and laser intensity regime

High-resolution spectroscopy of excited molecular states

Abstract

We use laser light near resonant with an optical bound-to-bound transition to shift the magnetic field at which a Feshbach resonance occurs. We operate in a regime of large detuning and large laser intensity. This reduces the light-induced atom-loss rate by one order of magnitude compared to our previous experiments [D.M. Bauer et al. Nature Phys. 5, 339 (2009)]. The experiments are performed in an optical lattice and include high-resolution spectroscopy of excited molecular states, reported here. In addition, we give a detailed account of a theoretical model that describes our experimental data.