Dynamic nonlinear (cubic) susceptibility in quantum Ising spin glass

TL;DR

This paper investigates the dynamic nonlinear cubic susceptibility in quantum Ising spin glasses, highlighting the influence of quantum fluctuations, droplet energy distributions, and length scales, with implications for experimental systems.

Contribution

It introduces a quantum droplet model to analyze nonlinear response, emphasizing the role of tunneling rates and quantum fluctuations in spin glasses.

Findings

Susceptibility depends strongly on droplet free energy distribution

Quantum fluctuations modulate the nonlinear response via tunneling rates

Results are compared with experiments on disordered dipolar quantum Ising magnets

Abstract

Dynamic nonlinear (cubic) susceptibility in quantum d-dimensional Ising spin glass with short-range interactions is investigated on the basis of quantum droplet model and quantum-mechanical nonlinear response theory. Nonlinear response depends on the tunneling rate for a droplet which regulates the strength of quantum fluctuations. It shows a strong dependence on the distribution of droplet free energies and on the droplet length scale average. Comparison with recent experiments on quantum spin glasses like disordered dipolar quantum Ising magnet is discussed.