Magnetic Gaps related to Spin Glass Order in Fermionic Systems

TL;DR

This paper investigates magnetic gaps linked to spin glass order in fermionic systems, providing model calculations that explain resistivity behavior and predicting a new metal-insulator transition influenced by spin-glass gaps.

Contribution

It introduces a theoretical framework connecting spin glass magnetic gaps with fermionic density of states and predicts a novel metal-insulator transition driven by spin-glass phenomena.

Findings

Evidence for magnetic gaps below freezing temperature

Model calculations explaining resistivity crossover

Prediction of a new metal-insulator transition

Abstract

We provide evidence for spin glass related magnetic gaps in the fermionic density of states below the freezing temperature. Model calculations are presented and proposed to be relevant for explaining resistivity measurements which observe a crossover from variable-range- to activated behavior. The magnetic field dependence of a hardgap and the low temperature decay of the density of states are given. In models with fermion transport a new metal-insulator transition is predicted to occur due to the spin-glass gap, anteceding the spin glass to quantum paramagnet transition at smaller spin density. Important fluctuation effects due to finite range frustrated interactions are estimated and discussed.