Dirac fermion heating, current scaling, and direct insulator-quantum Hall transition in multi-layer epitaxial graphene

Published

August 1, 2013

Author(s)

Randolph E. Elmquist, Fan-Hung Liu, Chang-Shun Hsu, Chiashain Chuang, Tak-Pong Woo, Lung-I Huang Huang, Chi-Te Laing, Yasuhiro Fukuyama, Yanfei Yang

Abstract

We have performed magnetotransport measurements on multi-layer 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 the 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 ~0.5.Such results are consistent with electron heating in conventional two-dimensional systems in the plateau-plateu transition regime. With increasing magnetic field B, we observe an I-independent point in the measured longitudinal resistivity rxx which is equivalent to the direct insulator-quantum Hall (I-QH) transition characterized by a temperature-independent point in rxx. Together with recent experimental evidence for the direct I-QHtransition, our new data suggests that such a transition is a universal effect in graphene, albeit further studies are required for obtaining a thorough understanding of such an effect.

Citation

Nanoscale Research Letter

Issue

8:360

Pub Type

Journals

Keywords

Quantum Hall effect, longitudinal resistivity, Dirac fermion

Citation

Elmquist, R. , Liu, F. , Hsu, C. , Chuang, C. , , T. , , L. , Laing, C. , Fukuyama, Y. and Yang, Y. (2013), Dirac fermion heating, current scaling, and direct insulator-quantum Hall transition in multi-layer epitaxial graphene, Nanoscale Research Letter (Accessed March 3, 2025)