Experimental studies of equilibrium vortex properties in a Bose-condensed gas

TL;DR

This paper investigates equilibrium vortex properties in a rotating Bose-Einstein condensate through precise measurements, numerical simulations, and comparison with theoretical models, focusing on vortex lattice spacing, core size, and temperature effects.

Contribution

It provides new experimental data on vortex lattice and core sizes across various densities and rotation rates, and compares these with recent theoretical predictions.

Findings

Vortex lattice spacing and core size measured accurately.

Experimental results align with certain theoretical models.

Finite temperature effects influence vortex contrast.

Abstract

We characterize several equilibrium vortex effects in a rotating Bose-Einstein condensate. Specifically we attempt precision measurements of vortex lattice spacing and the vortex core size over a range of condensate densities and rotation rates. These measurements are supplemented by numerical simulations, and both experimental and numerical data are compared to theory predictions of Sheehy and Radzihovsky [17] (cond-mat/0402637) and Baym and Pethick [25] (cond-mat/0308325). Finally, we study the effect of the centrifugal weakening of the trapping spring constants on the critical temperature for quantum degeneracy and the effects of finite temperature on vortex contrast.