Collective excitation of Bose-Einstein condensates in the transition region between 3D and 1D

TL;DR

This study measures the quadrupolar excitation frequency of Bose-Einstein condensates during the transition from three-dimensional to one-dimensional regimes, accounting for thermal effects and comparing with theoretical models.

Contribution

It provides experimental data on excitation frequencies in the 3D-1D transition, incorporating thermal coupling effects with a theoretical framework.

Findings

Frequency increases during the 3D to 1D transition

Experimental results agree with theoretical predictions

Thermal effects significantly influence excitation frequencies

Abstract

We measure the frequency of the low m=0 quadrupolar excitation mode of weakly interacting Bose-Einstein condensates in the transition region from the 3D to the 1D mean-field regime. Various effects shifting the frequency of the mode are discussed. In particular we take the dynamic coupling of the condensate with the thermal component at finite temperature into account using a time-dependent Hartree-Fock-Bogoliubov treatment developed in [S. Giorgini, Phys. Rev. A 61, 063615 (2000)]. We show that the frequency rises in the transition from 3D to 1D, in good agreement with the theoretical prediction [C. Menotti and S. Stringari, Phys. Rev. A 66, 043610 (2002)].