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Insulator-quantum Hall transition in monolayer epitaxial graphene



Lung-I Huang, Yanfei Yang, Randolph Elmquist, Shun-Tsung Lo, Fan-Hung H. Liu, Chi-Te Laing


We report on magneto-transport measurements on low-density, large-area monolayer epitaxial graphene devices grown on SiC. We observe temperature (T)-independent crossing points in the longitudinal resistivity (rho)sub(xx), which are signatures of the insulator-quantum Hall (I-QH) transition, in all three devices. Upon converting the raw data into longitudinal and Hall conductivities (sigma)sub(xx) and (sigma)sub(xy), in the most disordered device, we observed a T-driven flow diagram approximated by the semi-circle law as well as the T-independent point in (sigma)sub(xy) near e^2/h. We discuss our experimental results in the context of the evolution of the zero-energy Landau level at low magnetic fields B. We also compare the observed strongly insulating behaviour with metallic behaviour and the absence of the I-QH transition in graphene on SiO2 prepared by mechanical exfoliation.
RSC Advances


graphene, Landau level, quantum Hall effect, disorder, conductivity


Huang, L. , Yang, Y. , Elmquist, R. , Lo, S. , Liu, F. and Laing, C. (2016), Insulator-quantum Hall transition in monolayer epitaxial graphene, RSC Advances, [online], (Accessed April 23, 2024)
Created July 21, 2016, Updated October 12, 2021