Quantum Magnets with Anisotropic Infinite Range Random Interactions

TL;DR

This paper investigates the quantum dynamics of anisotropic disordered Heisenberg models with infinite-range interactions, revealing how anisotropy influences spin-glass behavior and order parameters at zero temperature.

Contribution

It introduces a quantum generalization of the classical Sherrington-Kirkpatrick model and analyzes the effects of anisotropy on spin-glass properties using exact diagonalization.

Findings

Behavior of Edwards Anderson order parameter varies with anisotropy.

Energy per spin shows distinct trends from Ising to Heisenberg limits.

Quantum effects significantly modify classical spin-glass characteristics.

Abstract

Using exact diagonalization techniques we study the dynamical response of the anisotropic disordered Heisenberg model for systems of S=1/2 spins with infinite range random exchange interactions at temperature T=0. The model can be considered as a generalization, to the quantum case, of the well known Sherrington-Kirkpatrick classical spin-glass model. We also compute and study the behavior of the Edwards Anderson order parameter and energy per spin as the anisotropy evolves from the Ising to the Heisenberg limits.