Probing quench dynamics across a quantum phase transition into a 2D Ising antiferromagnet

TL;DR

This paper experimentally investigates the real-time dynamics of a 2D Ising spin system crossing a quantum phase transition, revealing how correlations develop during the quench process using advanced atomic and imaging techniques.

Contribution

It demonstrates the first experimental study of quench dynamics in a 2D quantum Ising model with site-resolved measurements across a phase transition.

Findings

Observation of correlation buildup during the quench

Achievement of longer-range antiferromagnetic correlations

Comparison of experimental results with exact calculations

Abstract

Simulating the real-time evolution of quantum spin systems far out of equilibrium poses a major theoretical challenge, especially in more than one dimension. We experimentally explore the dynamics of a two-dimensional Ising spin system with transverse and longitudinal fields as we quench it across a quantum phase transition from a paramagnet to an antiferromagnet. We realize the system with a near unit-occupancy atomic array of over 200 atoms obtained by loading a spin-polarized band insulator of fermionic lithium into an optical lattice and induce short-range interactions by direct excitation to a low-lying Rydberg state. Using site-resolved microscopy, we probe the correlations in the system after a sudden quench from the paramagnetic state and compare our measurements to exact calculations in the regime where it is possible. We achieve many-body states with longer-range antiferromagnetic correlations by implementing a near-adiabatic quench and study the buildup of correlations as we cross the quantum phase transition at different rates.