Probing the Superfluid to Mott Insulator Transition at the Single Atom Level

TL;DR

This study uses single-atom imaging to explore the superfluid to Mott insulator transition in a Bose-Hubbard model, providing detailed local insights into quantum phase changes and dynamics.

Contribution

It introduces a site-resolved imaging technique to analyze the microscopic details of the phase transition in quantum gases.

Findings

Identified microscopic heterostructures of low entropy Mott domains

Measured local quantum dynamics and transition timescales

Provided a sensitive local thermometer based on fluctuations

Abstract

Quantum gases in optical lattices offer an opportunity to experimentally realize and explore condensed matter models in a clean, tunable system. We investigate the Bose-Hubbard model on a microscopic level using single atom-single lattice site imaging; our technique enables space- and time-resolved characterization of the number statistics across the superfluid-Mott insulator quantum phase transition. Site-resolved probing of fluctuations provides us with a sensitive local thermometer, allows us to identify microscopic heterostructures of low entropy Mott domains, and enables us to measure local quantum dynamics, revealing surprisingly fast transition timescales. Our results may serve as a benchmark for theoretical studies of quantum dynamics, and may guide the engineering of low entropy phases in a lattice.