Spectrum and correlation functions of a quasi-one-dimensional quantum Ising model

TL;DR

This paper investigates the phase diagram and dynamical magnetic susceptibility of weakly coupled quantum Ising chains, revealing that key quantum Ising physics persists in the ordered state and can be experimentally observed via neutron scattering.

Contribution

It provides a detailed analysis of the phase diagram and dynamical properties of a quasi-one-dimensional quantum Ising model using Bethe ansatz and RPA methods, highlighting observable quantum effects.

Findings

Quantum Ising chain physics survives in the ordered state

Dynamical susceptibility exhibits characteristic features

Neutron scattering can detect quantum effects

Abstract

We consider a model of weakly coupled quantum Ising chains. We describe the phase diagram of such a model and study the dynamical magnetic susceptibility by means of Bethe ansatz and the Random Phase Approximation applied to the inter-chain exchange. We argue that some of the beautiful physics of the quantum Ising chain in a magnetic field survives in the ordered state of the quasi-one-dimensional model and can be observed experimentally by means of neutron scattering.