Noise correlations in the expansion of an interacting 1D Bose gas from a regular array

TL;DR

This paper investigates how noise correlations evolve during the one-dimensional expansion of interacting bosons from a regular array, revealing a transition from bosonic peaks to fermionic dips with intermediate Fano resonances.

Contribution

It introduces a detailed analysis of noise correlations in an interacting 1D Bose gas during expansion, highlighting the transition from bosonic to fermionic behavior and identifying Fano resonance features.

Findings

Bosonic peaks in correlations without interactions

Fermionic dips at infinite repulsion

Fano resonance lineshapes at intermediate interactions

Abstract

We consider the one dimensional expansion of a system of interacting bosons, starting from a regular array. Without interactions the familiar Hanbury Brown and Twiss effect for bosons gives rise to a series of peaks in the density-density correlations of the expanded system. Infinitely repulsive particles likewise give a series of dips, a signature of the underlying description in terms of free fermions. In the intermediate case of finite interaction the noise correlations consist of a set of Fano resonance lineshapes, with an asymmetry parameter determined by the scattering phase shift of a pair of particles, and a width depending on the initial momentum spread of the particles.