Detecting phonons and persistent currents in toroidal Bose-Einstein condensates by means of pattern formation

TL;DR

This paper presents a theoretical study on how pattern formation in a toroidal Bose-Einstein condensate can be used to detect phonons and persistent currents, providing a method to analyze quantum and thermal fluctuations.

Contribution

It introduces a novel approach using density pattern formation from parametric amplification to measure phonon spectra and circulation in toroidal BECs.

Findings

Density patterns reveal the Bogoliubov spectrum.

Pattern formation enables sensitive detection of quantized circulation.

Thermal and quantum fluctuations influence the amplification process.

Abstract

We theoretically investigate the dynamic properties of a Bose-Einstein condensate in a toroidal trap. A periodic modulation of the transverse confinement is shown to produce a density pattern due to parametric amplification of phonon pairs. By imaging the density distribution after free expansion one obtains i) a precise determination of the Bogoliubov spectrum and ii) a sensitive detection of quantized circulation in the torus. The parametric amplification is also sensitive to thermal and quantum fluctuations.