Phonon Hall effect with first-principles calculations

TL;DR

This paper uses first-principles calculations to investigate the phonon Hall effect in real materials, providing new insights and benchmarks, especially in sodium chloride and barium titanate, and discusses the role of electronic Berry curvature.

Contribution

It introduces first-principles methods to study the phonon Hall effect in actual materials, bridging the gap between theory and experiment.

Findings

Benchmark of PHE in NaCl under high magnetic field

Demonstration of PHE in BTO

Discussion of deviations in STO results

Abstract

Phonon Hall effect (PHE) has attracted a lot of attention in recent years with many theoretical and experimental explorations published. While experiments work on complicated materials, theoretical studies are still hovering around the phenomenon-based models. Moreover, previous microscopic theory was found unable to explain large thermal Hall conductivity obtained by experiments in strontium titanate (STO). Therefore, as a first attempt to bridge this gap, we implement first-principles calculations to explore the PHE in real materials. Our work provides a new benchmark of the PHE in sodium chloride (NaCl) under a large external magnetic field. Moreover, we demonstrate our results in barium titanate (BTO), and discuss the results in STO in detail about their deviation from experiments. As a possible future direction, we further propose that the inner electronic Berry curvature plays an important role in the PHE in STO.