Lee-Yang zeros and two-time spin correlation function

TL;DR

This paper establishes a link between the zeros of a two-time spin correlation function and Lee-Yang zeros of the partition function, proposing a method to observe these zeros experimentally through correlation measurements.

Contribution

It introduces a novel approach to experimentally detect Lee-Yang zeros by measuring the time dependence of the two-time correlation function.

Findings

Zeros of the correlation function correspond to Lee-Yang zeros.

Measuring correlation functions enables direct observation of Lee-Yang zeros.

Provides a new experimental method for studying phase transitions.

Abstract

The two-time correlation function for probe spin interacting with spin system (bath) is studied. We show that zeros of this function correspond to zeros of partition function of spin system in complex magnetic field. The obtained relation gives new possibility to observe the Lee-Yang zeros experimentally. Namely, we show that measuring of the time dependence of correlation function allows direct experimental observation of the Lee-Yang zeros.