Effective Control of Cold Collisions with Radio Frequency Fields

TL;DR

This paper demonstrates how radio frequency fields can effectively control cold atom collisions and induce Feshbach resonances in rubidium-87, enabling manipulation of atomic interactions and molecule formation.

Contribution

It introduces a theoretical framework combining quantum defect theory and Floquet method to analyze RF-induced control of cold collisions and Feshbach resonances.

Findings

RF fields can significantly modify scattering lengths.

RF-induced Feshbach resonances occur in various magnetic field regimes.

RF fields can facilitate cold atom molecule formation.

Abstract

We study $^{87}$Rb cold collisions in a static magnetic field and a single-color radio frequency (RF) field by employing the multi-channel quantum defect theory in combination with the Floquet method to solve the two-body time-dependent Schr\"odinger equation. Our results show that RF fields can modify the two-body scattering length by a large scale through Feshbach resonances both in low and high static magnetic field regimes. Such RF induced Feshbach resonances can be applied to quenching experiments or controlling interactions in spinor condensates. Here, we also show that analogous to photo-association, RF fields can also associate cold atoms into molecules at a useful rate.