Physics of a disordered Dirac point in epitaxial graphene from temperature-dependent magnetotransport measurements
Journal article, 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

Author

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, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Samuel Lara Avila

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Sergey Kubatkin

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

R. Yakimova

Linköping University

R. J. Nicholas

University of Oxford

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 92 7 075407

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

European Commission (FP7), 2013-10-01 -- 2016-03-31.

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Subject Categories

Condensed Matter Physics

DOI

10.1103/PhysRevB.92.075407

More information

Latest update

5/29/2018