Effects of spin-orbit coupling and magnetic field on electronic properties of Germanene structure

TL;DR

This study models the electronic and optical properties of monolayer Germanene under magnetic field and spin-orbit coupling, revealing effects on conductivity, thermal properties, and thermopower using Kane-Mele Hamiltonian and Green's function methods.

Contribution

It introduces a Kane-Mele model with magnetic field and next-nearest neighbor hopping to analyze Germanene's electronic and optical behaviors, including dynamical conductivity and thermoelectric effects.

Findings

Finite Drude response at low frequency with magnetic field and spin-orbit coupling.

Enhanced Drude weight with electron doping.

Temperature increases thermal conductivity and specific heat.

Abstract

In this paper, we present a Kane-Mele model in the presence of magnetic field and next nearest neighbors hopping amplitudes for investigations the electronic and optical properties of monolayer Germanene. Specially, we address the dynamical conductivity of the structure as a function of photon frequency and in the presence of magnetic field and spin-orbit coupling at finite temperature. Using linear response theory and Green's function approach, the frequency dependence of optical conductivity has been obtained in the context of Kane-Mele model Hamiltonian. Our results show a finite Drude response at low frequency at non zero value for magnetic field in the presence of spin-orbit coupling. However Drude weight gets remarkable amount in the presence of electron doping. The thermal conductivity and specific heat increase with increasing the temperature at low amounts of temperature due to the increasing of thermal energy of charge carriers and excitation of them to the conduction bands. The results for Seebeck coefficient show the sign of thermopower is negative in the presence of spin-orbit coupling. Also we have studied the temperature dependence of electrical conductivity of Germanene monolayer due to both spin orbit coupling and magnetic field factors in details.