Spin caloritronics in collinear ferromagnetic helical structures under irradiation

TL;DR

This paper investigates how polarized light affects charge and spin thermoelectric properties in ferromagnetic helical structures, revealing light-induced spin-split transmission and enhanced spin thermoelectric efficiency.

Contribution

It introduces a comprehensive analysis of light irradiation effects on spin-dependent thermoelectric responses using Floquet-Bloch and Green's function methods.

Findings

Light irradiation induces spin-split transmission features.

Thermal conductance is suppressed by light.

Spin figure of merit outperforms charge FOM under various conditions.

Abstract

We study the charge and spin-dependent thermoelectric response of a ferromagnetic helical system irradiated by arbitrarily polarized light, using a tight-binding framework and the Floquet-Bloch formalism. Transport properties for individual spin channels are determined by employing the non-equilibrium Green's function technique, while phonon thermal conductance is evaluated using a mass-spring model with different lead materials. The findings reveal that that light irradiation induces spin-split transmission features, suppresses thermal conductance, and yields favorable spin thermopower and figure of merit (FOM). The spin FOM consistently outperforms its charge counterpart under various light conditions. Moreover, long-range hopping is shown to enhance the spin thermoelectric performance, suggesting a promising strategy for efficient energy conversion in related ferromagnetic systems.