Spectroscopy of elementary excitations from quench dynamics in a dipolar XY Rydberg simulator

TL;DR

This paper introduces quench spectroscopy using a Rydberg quantum simulator to probe low-energy excitations in a 2D dipolar XY model, revealing distinct behaviors for ferro- and anti-ferromagnetic couplings.

Contribution

It demonstrates a novel spectroscopy method that measures excitation spectra through spin correlation dynamics after a quench in a Rydberg system.

Findings

Ferro- and anti-ferromagnetic couplings show different excitation behaviors.

Ferromagnet exhibits linear spin wave excitations.

Antiferromagnet shows decay of spin waves, indicating nonlinearities.

Abstract

We use a Rydberg quantum simulator to demonstrate a new form of spectroscopy, called quench spectroscopy, which probes the low-energy excitations of a many-body system. We illustrate the method on a two-dimensional simulation of the spin-1/2 dipolar XY model. Through microscopic measurements of the spatial spin correlation dynamics following a quench, we extract the dispersion relation of the elementary excitations for both ferro- and anti-ferromagnetic couplings. We observe qualitatively different behaviors between the two cases that result from the long-range nature of the interactions, and the frustration inherent in the antiferromagnet. In particular, the ferromagnet exhibits elementary excitations behaving as linear spin waves. In the anti-ferromagnet, spin waves appear to decay, suggesting the presence of strong nonlinearities. Our demonstration highlights the importance of power-law interactions on the excitation spectrum of a many-body system.