Condensed Matter Seminar Series

Quantum transport in disordered graphene: weak localisation and mesoscopics

Vladimir Fal'ko

Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK

MONDAY April 27,  11:00 am,  Room 298,  Physics Building

Abstract:  Weak localisation of electrons in weakly disordered graphene was studied in the regime of high carrier densities. The proposed theory includes symmetry classification of disorder in monolayer (and bilayer [2]) graphene, analysis of the role of trigonal warping in the band structure, bond disorder, sublattice asymmetry and the intervalley scattering. Weak localisation magnetoresistance in graphene has been observed in a number of experiments, and we show that this can be used to extract information about, e.g., intervalley scattering in graphene samples. By analysing universal conductance fluctuations in graphene nanostructures [3] we show how the correlation function of conductance fluctuations can be used to deternine temperature of electrons in graphene [4] (which may strongly differ from the thermal bath temperature due to a poor heat contact with the electrodes/substrate).

[1] E. McCann, K. Kechedzhi, V. Fal’ko, H. Suzuura, T. Ando, and B. Altshuler, Phys. Rev. Lett. 97, 146805 (2006)

[2] K. Kechedzhi, V. Fal’ko, E. McCann, and B. Altshuler, Phys. Rev. Lett. 98, 176806 (2007)

[3] K. Kechedzhi, O. Kashuba, and V. Fal’ko, Phys. Rev. B 77, 193403 (2008)

[4] K. Kechedzhi, D. Horsell, F. Tikhonenko, A. Savchenko, R. Gorbachev, I. Lerner, and V. Fal’ko - Phys. Rev. Lett. 102, 066801 (2009)