Asymmetric superradiant scattering and abnormal mode amplification induced by atomic density distortion

TL;DR

This paper investigates how atomic density distortions in a Bose-Einstein condensate cause asymmetric superradiant scattering and abnormal mode amplification, revealing new insights into matter-wave superradiance influenced by geometric asymmetries.

Contribution

It demonstrates that small density distortions can induce significant asymmetries in superradiant scattering modes and introduces a method to probe atomic density profiles via superradiance.

Findings

Asymmetric scattering modes are induced by minor density variations.

Optical field amplification is greater in the dilute regions of the cloud.

Numerical simulations align with experimental observations.

Abstract

The superradiant Rayleigh scattering using a pump laser incident along the short axis of a Bose-Einstein condensate with a density distortion is studied, where the distortion is formed by shocking the condensate utilizing the residual magnetic force after the switching-off of the trapping potential. We find that very small variation of the atomic density distribution would induce remarkable asymmetrically populated scattering modes by the matter-wave superradiance with long time pulse. The optical field in the diluter region of the atomic cloud is more greatly amplified, which is not an ordinary mode amplification with the previous cognition. Our numerical simulations with the density envelop distortion are consistent with the experimental results. This supplies a useful method to reflect the geometric symmetries of the atomic density profile by the superradiance scattering.