Cross-Molecular Coupling in Combined Photoassociation and Feshbach Resonances

TL;DR

This paper models the interaction between photoassociation and Feshbach resonances in a Bose-Einstein condensate, revealing quantum interference effects and tunable loss features due to cross-molecular coupling.

Contribution

It introduces a theoretical model for combined resonances showing how cross coupling causes dispersive shifts and quantum interference effects, with tunable Feshbach loss features.

Findings

Dispersive shift in laser resonance position due to cross coupling

Quantum interference enables control of photoassociation

Feshbach loss features are tunable with laser intensity

Abstract

We model combined photoassociation and Feshbach resonances in a Bose-Einstein condensate. When the magnetic field is far-off resonance, cross coupling between the two target molecules--enabled by the shared dissociation continuum--leads to an anomalous dispersive shift in the position of laser resonance, as well as unprecedented elimination and enhancement of resonant photoassociation via quantum interference. For off-resonant lasers, a dispersive shift and quantum interference appear similarly in resonant three-body Feshbach losses, except that the Feshbach node is tunable with intensity.