Physics of a disordered Dirac point in epitaxial graphene from temperature-dependent magnetotransport measurements
Artikel i vetenskaplig tidskrift, 2015

We report a study of disorder effects on epitaxial graphene in the vicinity of the Dirac point by magnetotransport. Hall effect measurements show that the carrier density increases quadratically with temperature, in good agreement with theoretical predictions which take into account intrinsic thermal excitation combined with electron-hole puddles induced by charged impurities. We deduce disorder strengths in the range 10.2-31.2 meV, depending on the sample treatment. We investigate the scattering mechanisms and estimate the impurity density to be 3.0-9.1x10(10) cm(-2) for our samples. A scattering asymmetry for electrons and holes is observed and is consistent with theoretical calculations for graphene on SiC substrates. We also show that the minimum conductivity increases with increasing disorder strength, in good agreement with quantum-mechanical numerical calculations.

Physics

boron-nitride

scattering

transport

Författare

J. Huang

University of Oxford

J. A. Alexander-Webber

University of Oxford

A. M. R. Baker

University of Oxford

Tjbm Janssen

National Physical Laboratory (NPL)

A.Y. Tzalenchuk

Royal Holloway University of London

National Physical Laboratory (NPL)

V. Antonov

Royal Holloway University of London

Thomas Yager

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Samuel Lara Avila

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Sergey Kubatkin

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

R. Yakimova

Linköpings universitet

R. J. Nicholas

University of Oxford

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 92 075407

Graphene-Based Revolutions in ICT And Beyond (Graphene Flagship)

Europeiska kommissionen (FP7), 2013-10-01 -- 2016-03-31.

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1103/PhysRevB.92.075407