Probing Matter-Field and Atom-Number Correlations in Optical Lattices by Global Nondestructive Addressing

TL;DR

This paper demonstrates how light scattering can noninvasively reveal both density and matter-field correlations in ultracold gases within optical lattices, providing insights into phase transitions and quantum properties.

Contribution

It introduces a method to probe matter-field and atom-number correlations globally through nondestructive light scattering, including enhanced detection techniques and generalized Bragg conditions.

Findings

Light scattering reveals density and matter-field correlations.

The method distinguishes phases like Mott insulator, superfluid, and Bose glass.

Scattering peaks can occur even when classical diffraction is suppressed.

Abstract

We show that light scattering from an ultracold gas reveals not only density correlations, but also matter-field interference at its shortest possible distance in an optical lattice, which defines key properties such as tunneling and matter-field phase gradients. This signal can be enhanced by concentrating probe light between lattice sites rather than at density maxima. As addressing between two single sites is challenging, we focus on global nondestructive scattering, allowing probing order parameters, matter-field quadratures and their squeezing. The scattering angular distribution displays peaks even if classical diffraction is forbidden and we derive generalized Bragg conditions. Light scattering distinguishes all phases in the Mott insulator - superfluid - Bose glass phase transition.