Quantum Corrections to Thermopower and Conductivity in Graphene

TL;DR

This paper investigates quantum corrections to conductivity and thermopower in graphene using numerical and analytical methods, revealing large magnetothermopower sensitive to impurities, and compares results with experiments to estimate impurity characteristics.

Contribution

It introduces a combined numerical and analytical approach to analyze quantum corrections in graphene and demonstrates how magnetothermopower measurements can determine impurity properties.

Findings

Large magnetothermopower observed due to quantum corrections.

Impurity size and strength can be inferred from thermopower measurements.

Theoretical results align with experimental data on graphene's magnetoconductance.

Abstract

The quantum corrections to the conductivity and the thermopower in monolayer graphene are studied. We use the recursive Green's function method to calculate numerically the conductivity and the thermopower of graphene. We then analyze these weak localization corrections by fitting with the analytical theory as function of the impurity parameters and the gate potential. As a result of the quantum corrections to the thermopower, we find large magnetothermopower which is shown to provide a very sensitive measure of the size and strength of the impurities. We compare these analytical and numerical results with existing experimental measurements of magnetoconductance of single layer graphene and find that the average size and strength of the impurities in these samples can thereby be determined. We suggest favorable parameter ranges for future measurements of the magnetothermopower.