Quasi-2D Confinement of a BEC in a Combined Optical and Magnetic Potential

TL;DR

This paper demonstrates creating a highly anisotropic hybrid optical-magnetic trap for ultracold atoms, enabling the confinement of Bose-Einstein condensates in a Quasi-2D regime, verified through experimental measurements and modeling.

Contribution

The study introduces a novel hybrid trap combining optical and magnetic potentials to achieve strong axial confinement for ultracold atoms.

Findings

Achieved axial confinement frequency of 2.2 kHz for rubidium.

Successfully confined ~10^5 atoms in a Quasi-2D regime.

Experimental results agree with a variational model.

Abstract

We have added an optical potential to a conventional Time-averaged Orbiting Potential (TOP) trap to create a highly anisotropic hybrid trap for ultracold atoms. Axial confinement is provided by the optical potential; the maximum frequency currently obtainable in this direction is 2.2 kHz for rubidium. The radial confinement is independently controlled by the magnetic trap and can be a factor of 700 times smaller than in the axial direction. This large anisotropy is more than sufficient to confine condensates with ~10^5 atoms in a Quasi-2D (Q2D) regime, and we have verified this by measuring a change in the free expansion of the condensate; our results agree with a variational model.