Tests of Conformal Field Theory at the Yang-Lee Singularity

TL;DR

This study investigates the Yang-Lee edge singularity in the 2D Ising model using quantum spin chains and transfer matrix methods, confirming its consistency with minimal conformal field theory predictions.

Contribution

It provides the first detailed numerical verification of the conformal field theory description of the Yang-Lee singularity in the 2D Ising model.

Findings

Excitation spectrum matches CFT predictions

Single structure constant evaluated and consistent with theory

Results confirm the (A4;A1) minimal model description

Abstract

This paper studies the Yang-Lee edge singularity of 2-dimensional (2D) Ising model based on a quantum spin chain and transfer matrix measurements on the cylinder. Based on finite-size scaling, the low-lying excitation spectrum is found at the Yang-Lee edge singularity. Based on transfer matrix techniques, the single structure constant is evaluated at the Yang-Lee edge singularity. The results of both types of measurements are found to be fully consistent with the predictions for the (A4;A1)minimal conformal field theory, which was previously identified with this critical point.