Dirac fermion heating, current scaling, and direct insulator-quantum hall transition in multilayer epitaxial graphene
Journal
Nanoscale Research Letters
Journal Volume
8
Journal Issue
1
Pages
1-6
Date Issued
2013
Author(s)
Liu, F.-H.
Hsu, C.-S.
Chuang, C.
Woo, T.-P.
Huang, L.
Lo, S.-T.
Fukuyama, Y.
Yang, Y.
Elmquist, R.E.
Abstract
We have performed magnetotransport measurements on multilayer epitaxial graphene. By increasing the driving current I through our graphene devices while keeping the bath temperature fixed, we are able to study Dirac fermion heating and current scaling in such devices. Using zero-field resistivity as a self thermometer, we are able to determine the effective Dirac fermion temperature (TDF) at various driving currents. At zero field, it is found that TDF ∝ I≈1/2. Such results are consistent with electron heating in conventional two-dimensional systems in the plateau-plateau transition regime. With increasing magnetic field B, we observe an I-independent point in the measured longitudinal resistivity ρxx which is equivalent to the direct insulator-quantum Hall (I-QH) transition characterized by a temperature-independent point in ρxx. Together with recent experimental evidence for direct I-QH transition, our new data suggest that such a transition is a universal effect in graphene, albeit further studies are required to obtain a thorough understanding of such an effect.
SDGs
Type
journal article