Critical properties of 1-D spin 1/2 antiferromagnetic Heisenberg model

TL;DR

This paper investigates the critical behavior of the one-dimensional spin-1/2 antiferromagnetic Heisenberg model, focusing on the effects of next-nearest neighbor interactions and magnetic fields, using numerical methods to analyze excitations and structure factors.

Contribution

It provides numerical analysis of the model's critical properties, including the effects of next-nearest neighbor coupling and magnetic fields, highlighting zero frequency excitations and soft modes.

Findings

Identification of zero frequency excitations at field-dependent momenta

Finite size scaling of static structure factors reveals critical behavior

Analysis of soft mode development under varying magnetic fields

Abstract

We discuss numerical results for the 1-D spin 1/2 antiferromagnetic Heisenberg model with next-to-nearest neighbour coupling and in the presence of an uniform magnetic field. The model develops zero frequency excitations at field dependent soft mode momenta. We compute critical quantities from finite size dependence of static structure factors.