RF coupling of a Bose-Einstein condensate in a TOP trap

TL;DR

This paper investigates how RF transitions couple a Bose-Einstein condensate in a TOP trap, revealing complex spatial dynamics influenced by the trap's time-varying field and multiple Zeeman states.

Contribution

It demonstrates the complex effects of the TOP trap's oscillating field on RF coupling and the resulting spatial structures in the condensate.

Findings

Rabi frequency varies spatially across the condensate

Time-varying detuning causes complex spatial patterns

Coupling process is strongly affected by the trap's oscillating field

Abstract

A radio frequency (RF) transition is used to convert a pure F=2,mF=2 87Rb Bose-Einstein condensate confined in a TOP trap to a mixture of F=2,mF=2 and F=2,mF=1 states. We show that the nature of this coupling process is strongly influenced by the presence of the time varying field of the TOP trap, and complicated by the presence of multiple Zeeman substates. In particular, the effective Rabi frequency associated with the applied RF field is not constant across the spatial extent of the cloud leading to a complex geometry for atom-laser output coupling and `averaging out' of Rabi oscillations. Further a time-varying detuning can give rise to complex spatial structures.