Unconventional critical activated scaling of two-dimensional quantum spin-glasses

TL;DR

This study investigates the critical behavior of 2D quantum spin glasses, revealing that their quantum criticality is governed by an infinite randomness fixed point, independent of bond distribution type.

Contribution

It demonstrates that the quantum critical behavior of 2D short-range spin glasses is governed by an infinite randomness fixed point, regardless of bond distribution.

Findings

Universality class independent of bond distribution

Quantum critical behavior governed by infinite randomness fixed point

Finite-size scaling confirms unconventional critical scaling

Abstract

We study the critical behavior of two-dimensional short-range quantum spin glasses by numerical simulations. Using a parallel tempering algorithm, we calculate the Binder cumulant for the Ising spin glass in a transverse magnetic field with two different short-range bond distributions, the bimodal and the Gaussian ones. Through an exhaustive finite-size scaling analysis, we show that the universality class does not depend on the exact form of the bond distribution but, most important, that the quantum critical behavior is governed by an infinite randomness fixed point.