Anisotropic thermoelectric effect in helimagnetic tunnel junctions

TL;DR

This paper theoretically investigates the anisotropic thermoelectric effects in helimagnetic tunnel junctions, revealing symmetry-dependent charge and spin thermopower influenced by the spiral magnetic order.

Contribution

It introduces a phenomenological theory linking the magnetic order topology to thermoelectric anisotropy in heterojunctions.

Findings

Charge and spin thermopower exhibit $C_{2v}$ symmetry.

Thermoelectric effects depend on magnetization orientation.

Effective spin-orbit interaction is key to anisotropy.

Abstract

Thermoelectric transport across normal-metal/helical-multiferroic/ferromagnetic heterojunctions is theoretically investigated. We find a anisotropic charge and spin thermopower with a $C_{2v}$ symmetry. The angular dependence on the magnetization orientation of the ferromagnetic layer is substantiated by a phenomenological theory based on the symmetry of the effective spin-orbit interaction induced by the topology of the spiral magnetic order in the multiferroic barrier.