Measurement of the ac Stark shift with a guided matter-wave interferometer

TL;DR

This paper demonstrates a guided-wave Bose-Einstein condensate interferometer to measure the ac Stark shift in rubidium atoms, revealing phase shifts and broadening effects near resonance, with potential for quantum state control.

Contribution

It introduces a practical guided-wave interferometer setup for precise ac Stark shift measurements and observes nonlinear effects near atomic resonance.

Findings

Measured ac polarizability near resonance matches theoretical predictions

Observed broadening of transition indicating collective light scattering

Potential for generating squeezed quantum states

Abstract

We demonstrate the effectiveness of a guided-wave Bose-Einstein condensate interferometer for practical measurements. Taking advantage of the large arm separations obtainable in our interferometer, the energy levels of the 87Rb atoms in one arm of the interferometer are shifted by a calibrated laser beam. The resulting phase shifts are used to determine the ac polarizability at a range of frequencies near and at the atomic resonance. The measured values are in good agreement with theoretical expectations. However, we observe a broadening of the transition near the resonance, an indication of collective light scattering effects. This nonlinearity may prove useful for the production and control of squeezed quantum states.