Absence of an equilibrium ferromagnetic spin glass phase in three dimensions

TL;DR

This study investigates the phase transition in three-dimensional spin glasses, providing evidence against the existence of a ferromagnetic spin glass phase and supporting the universality of the ferromagnetic transition exponents.

Contribution

It offers new computational evidence showing the absence of a ferromagnetic spin glass phase in 3D, challenging existing theoretical models.

Findings

Replica symmetry breaking persists up to the critical point.

No ferromagnetic spin glass phase is observed.

Ferromagnetic transition exponents are universal.

Abstract

Using ground state computations, we study the transition from a spin glass to a ferromagnet in 3-d spin glasses when changing the mean value of the spin-spin interaction. We find good evidence for replica symmetry breaking up till the critical value where ferromagnetic ordering sets in, and no ferromagnetic spin glass phase. This phase diagram is in conflict with the droplet/scaling and mean field theories of spin glasses. We also find that the exponents of the second order ferromagnetic transition do not depend on the microscopic Hamiltonian, suggesting universality of this transition.