Proximity-induced spin-polarized magnetocaloric effect in transition metal dichalcogenides

TL;DR

This paper investigates how proximity to a ferromagnetic substrate induces a spin-polarized magnetocaloric effect in a 2D transition metal dichalcogenide, enabling tunable thermal responses for potential spintronic applications.

Contribution

It models the proximity-induced MCE in MoTe₂ on EuO, revealing large spin-polarized entropy changes and tunability via gating, which is a novel approach in 2D magnetic heterostructures.

Findings

Large spin-polarized entropy changes observed outside the MoTe₂ band gap.

Gating can switch the MCE between heating and cooling for different spins.

Rashba field influences the magnitude and sign of the MCE in valence and conduction bands.

Abstract

We explore proximity-induced magnetocaloric effect (MCE) on transition metal dichalcogenides, focusing on a two-dimensional (2D) MoTe$_2$ monolayer deposited on a ferromagnetic semiconductor EuO substrate connected to a heat source. We model this heterostructure using a tight-binding model, incorporating exchange and Rashba fields induced by proximity to EuO, and including temperature through Fermi statistics. The MCE is induced on the 2D MoTe$_2$ layer due to the EuO substrate, revealing large spin-polarized entropy changes for energies out of the band gap of the MoTe$_2$-EuO system. By gating the chemical potential, the MCE can be tuned to produce heating for spin up and cooling for spin down across the $K$ and $K'$ valley splitting in the valence band, whereas either heats or cools for both spins in the conduction band. The Rashba field enhances the MCE in the valence zone while decreasing it in the conduction bands. The exchange field-induced MCE could be useful to produce tunable spin-polarized thermal responses in magnetic proximitized 2D materials.