Magnetoresistance of disordered graphene: From low to high temperatures
Abstract
We present the magnetoresistance (MR) of highly doped monolayer graphene layers grown by chemical vapor deposition on 6H-SiC. The magnetotransport studies are performed on a large temperature range, from T=1.7 K up to room temperature. The MR exhibits a maximum in the temperature range 120-240 K. The maximum is observed at intermediate magnetic fields (B =2-6 T), in between the weak localization and the Shubnikov-de Haas regimes. It results from the competition of two mechanisms. First, the low-field magnetoresistance increases continuously with T and has a purely classical origin. This positive MR is induced by thermal averaging and finds its physical origin in the energy dependence of the mobility around the Fermi energy. Second, the high-field negative MR originates from the electron-electron interaction (EEI). The transition from the diffusive to the ballistic regime is observed. The amplitude of the EEI correction points towards the coexistence of both long- and short-range disorder in these samples.
- Publication:
-
Physical Review B
- Pub Date:
- July 2014
- DOI:
- 10.1103/PhysRevB.90.035423
- arXiv:
- arXiv:1406.6255
- Bibcode:
- 2014PhRvB..90c5423J
- Keywords:
-
- 72.80.Vp;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- doi:10.1103/PhysRevB.90.035423