Tuning the scattering length with an optically induced Feshbach resonance

TL;DR

This paper demonstrates the optical control of atomic interactions in a Bose-Einstein condensate by tuning the scattering length using an optically induced Feshbach resonance, enabling precise manipulation of quantum gases.

Contribution

It experimentally shows how laser light near a molecular transition can tune the scattering length in a BEC, providing a new method for interaction control.

Findings

Successfully tuned scattering length over a wide range

Used Bragg spectroscopy for rapid measurement

Confirmed theoretical predictions of optical Feshbach resonance

Abstract

We demonstrate optical tuning of the scattering length in a Bose-Einstein condensate as predicted by Fedichev {\em et al.} [Phys. Rev. Lett. {\bf 77}, 2913 (1996)]. In our experiment atoms in a $^{87}$Rb condensate are exposed to laser light which is tuned close to the transition frequency to an excited molecular state. By controlling the power and detuning of the laser beam we can change the atomic scattering length over a wide range. In view of laser-driven atomic losses we use Bragg spectroscopy as a fast method to measure the scattering length of the atoms.