%0 Journal Article
%T Magnetic field driven ambipolar quantum Hall effect in epitaxial graphene close to the charge neutrality point
%+ Laboratoire Charles Coulomb (L2C)
%+ الجامعة اللبنانية [بيروت] = Lebanese University [Beirut] = Université libanaise [Beyrouth] (LU / ULB)
%+ Laboratoire national des champs magnétiques intenses - Toulouse (LNCMI-T)
%+ American University of The Middle East [Eqaila]
%+ Centre de Nanosciences et de Nanotechnologies [Marcoussis] (C2N)
%+ Paul Scherrer Institute (PSI)
%+ Linköping University (LIU)
%+ Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation (IMEP-LAHC )
%A Nachawaty, Abir
%A Yang, M.
%A Desrat, Wilfried
%A Nanot, Sébastien
%A Jabakhanji, B.
%A Kazazis, D.
%A Yakimova, R.
%A Cresti, A.
%A Escoffier, Walter
%A Jouault, Benoit
%< avec comité de lecture
%Z CMNE
%@ 2469-9950
%J Physical Review B
%I American Physical Society
%V 96
%N 7
%P 075442
%8 2017-08-15
%D 2017
%R 10.1103/PhysRevB.96.075442
%Z Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
%Z Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con]Journal articles
%X We have investigated the disorder of epitaxial graphene close to the charge neutrality point (CNP) by various methods: (i) at room temperature, by analyzing the dependence of the resistivity on the Hall coefficient; (ii) by fitting the temperature dependence of the Hall coefficient down to liquid helium temperature; (iii) by fitting themagnetoresistances at low temperature. All methods converge to give a disorder amplitude of (20±10) meV. Because of this relatively low disorder, close to the CNP, at low temperature, the sample resistivity does not exhibit the standard value~h/4e^2 but diverges. Moreover, themagnetoresistance curves have a unique ambipolar behavior,which has been systematically observed for all studied samples.This is a signature of both asymmetry in the density of states and in-plane charge transfer. The microscopic origin of this behavior cannot be unambiguously determined. However, we propose a model in which the SiC substrate steps qualitatively explain the ambipolar behavior.
%G English
%2 https://hal.science/hal-01584484/document
%2 https://hal.science/hal-01584484/file/PhysRevB.96.075442.pdf
%L hal-01584484
%U https://hal.science/hal-01584484
%~ UNIV-SAVOIE
%~ UNIV-TLSE3
%~ UGA
%~ CNRS
%~ UNIV-PSUD
%~ INSA-TOULOUSE
%~ INPG
%~ L2C
%~ IMEP-LAHC
%~ UNIV-PARIS-SACLAY
%~ UNIV-PSUD-SACLAY
%~ MIPS
%~ UNIV-MONTPELLIER
%~ LNCMI
%~ INSA-GROUPE
%~ UP-SCIENCES
%~ UGA-COMUE
%~ USMB-COMUE
%~ ANR
%~ GS-PHYSIQUE
%~ INSTITUT-SCIENCES-LUMIERE
%~ UNIV-UT3
%~ UT3-INP
%~ UT3-TOULOUSEINP
%~ UM-2015-2021
%~ C2N
%~ CROMA