Theory of the giant thermal Hall effect in the high temperature superconductors

TL;DR

This paper explains the giant thermal Hall effect observed in high-temperature superconductors' pseudogap phase as an orbital magnetic response of a quantum Heisenberg antiferromagnet, linking it to antiferromagnetic correlations.

Contribution

It provides a theoretical understanding of the giant thermal Hall effect in pseudogap phases as an orbital response in a quantum Heisenberg model with multi-spin exchange, connecting it to the pseudogap's origin.

Findings

Giant thermal Hall effect explained as orbital magnetic response

Correlation between the effect and antiferromagnetic interactions

Implication for the pseudogap mechanism

Abstract

Recent transport measurement finds giant negative thermal Hall signal in the pseudo-gap phase of the high temperature superconductors\cite{Taillefer}. Such a signal is found to increase in magnitude with decreasing doping and to reach its maximum in the half-filled antiferromagnetic ordered parent compounds. It is still elusive what is the implication of such a phenomena for the mechanism of the pseudo-gap phase. The observation of such a signal may also challenge our well established understanding of the parent compounds as perfect Heisenberg antiferromagnets. Here we show that such a giant thermal Hall effect can be naturally understood as the orbital magnetic response of a quantum Heisenberg antiferromagnet with sizable multi-spin exchange coupling. We also argue that the observation of the giant thermal Hall effect in the pseudo-gap phase imply that the origin of the pseudo-gap in the high temperature superconductors is closely related to the antiferromagnetic correlation between local spins.