Anomalous thermospin effect in the low-buckled Dirac materials

TL;DR

This paper investigates the anomalous thermospin effect in low-buckled Dirac materials like silicene, highlighting how their unique electronic structure leads to a strong spin Nernst effect influenced by carrier concentration and electric fields.

Contribution

It introduces a modified Kubo formalism accounting for effective magnetization in Dirac materials, providing a new approach to accurately calculate thermoelectric coefficients.

Findings

Demonstrates the role of effective magnetization in thermoelectric calculations.

Shows the dependence of the spin Nernst effect on carrier concentration and electric field.

Provides a theoretical framework for anomalous thermospin phenomena in Dirac materials.

Abstract

A strong spin Nernst effect with nontrivial dependences on the carrier concentration and electric field applied is expected in silicene and other low-buckled Dirac materials. These Dirac materials can be considered as being made of two independent electron subsystems of the two-component gapped Dirac fermions. For each subsystem the gap breaks a time-reversal symmetry and thus plays a role of an effective magnetic field. Accordingly, the standard Kubo formalism has to be altered by including the effective magnetization in order to satisfy the third law of thermodynamics. We explicitly demonstrate this by calculating the magnetization and showing how the correct thermoelectric coefficient emerges.