Thermoelectric Transport of Massive Dirac Fermions in Bilayer Graphene

TL;DR

This study measures thermoelectric power in bilayer graphene across various temperatures and densities, revealing behaviors consistent with semiclassical models at low temperatures and deviations at high temperatures, influenced by carrier density and magnetic fields.

Contribution

It provides detailed experimental insights into thermoelectric transport in bilayer graphene, highlighting the effects of carrier density, temperature, and magnetic field on thermoelectric phenomena.

Findings

TEP follows Mott formula at low temperatures

High carrier density TEP shows linear temperature dependence

Oscillating TEP and Nernst effect explained by 2D system behavior

Abstract

Thermoelectric power (TEP) is measured in bilayer graphene for various temperatures and charge-carrier densities. At low temperatures, measured TEP well follows the semiclassical Mott formula with a hyperbolic dispersion relation. TEP for a high carrier density shows a linear temperature dependence, which demonstrates a weak electron-phonon interaction in the bilayer graphene. For a low carrier density, a deviation from the Mott relation is observed at high temperatures and is attributed to the low Fermi temperature in the bilayer graphene. Oscillating TEP and the Nernst effect for varying carrier density, observed in a high magnetic field, are qualitatively explained by the two dimensionality of the system.