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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.
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], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=917328
(Accessed October 7, 2025)