Density fluctuations of a hard-core Bose gas in a one-dimensional lattice

TL;DR

This paper investigates the density fluctuations in a one-dimensional hard-core Bose gas, revealing oscillations in correlations and phase transition signatures, with robustness against weak confining potentials.

Contribution

It provides a detailed analysis of density correlations and structure factors during the transition from incommensurate to Mott insulating phases in 1D Bose gases.

Findings

Density-density correlation oscillations with diverging wavelength at transition

Vanishing static structure factor near Mott insulator phase

Oscillation behavior persists under weak confinement

Abstract

For a hard-core Bose gas on a one-dimensional lattice we find characteristic oscillations in the density-density correlation function. Their wavelength diverges as the system undergoes a continuous transition from an incommensurate to a Mott insulating phase. The associated static structure factor vanishes as the Mott insulating phase is approached. The qualitative picture is unchanged when a weak confinig potential is applied to the system.