Bose-Einstein condensation in dark power-law laser traps

TL;DR

This paper proposes a new method to achieve Bose-Einstein condensation using dark power-law laser traps created by crossing blue-detuned Laguerre-Gaussian beams, enabling exploration of various trapping geometries and higher transition temperatures.

Contribution

It introduces a novel trapping technique with Laguerre-Gaussian beams that allows for diverse power-law potentials and improved condensation conditions compared to harmonic traps.

Findings

Higher transition temperatures in power-law traps for fixed atom number.

Formation of quasi-homogeneous Bose gases in square-well potentials.

Acceleration of condensation dynamics with focused Laguerre-Gaussian beams.

Abstract

We investigate theoretically an original route to achieve Bose-Einstein condensation using dark power-law laser traps. We propose to create such traps with two crossing blue-detuned Laguerre-Gaussian optical beams. Controlling their azimuthal order $\ell$ allows for the exploration of a multitude of power-law trapping situations in one, two and three dimensions, ranging from the usual harmonic trap to an almost square-well potential, in which a quasi-homogeneous Bose gas can be formed. The usual cigar-shaped and disk-shaped Bose-Einstein condensates obtained in a 1D or 2D harmonic trap take the generic form of a "finger" or of a "hockey puck" in such Laguerre-Gaussian traps. In addition, for a fixed atom number, higher transition temperatures are obtained in such configurations when compared with a harmonic trap of same volume. This effect, which results in a substantial acceleration of the condensation dynamics, requires a better but still reasonable focusing of the Laguerre-Gaussian beams.