Work

Phase Space for the Breakdown of the Quantum Hall Effect in Epitaxial Graphene

Year: 2013

Type: article

Abstract: We report the phase space defined by the quantum Hall effect breakdown in polymer gated epitaxial graphene on SiC $(\mathrm{SiC}/\mathrm{G})$ as a function of temperature, current, carrier density, and magnetic fields up to 30 T. At 2 K, breakdown currents (${I}_{c}$) almost 2 orders of magnitude greater than in GaAs devices are observed. The phase boundary of the dissipationless state (${\ensuremath{\rho}}_{xx}=0$) shows a [$1\ensuremath{-}(T/{T}_{c}{)}^{2}$] dependence and persists up to ${T}_{c}>45\text{ }\text{ }\mathrm{K}$ at 29 T. With magnetic field ${I}_{c}$ was found to increase $\ensuremath{\propto}{B}^{3/2}$ and ${T}_{c}\ensuremath{\propto}{B}^{2}$. As the Fermi energy approaches the Dirac point, the $\ensuremath{\nu}=2$ quantized Hall plateau appears continuously from fields as low as 1 T up to at least 19 T due to a strong magnetic field dependence of the carrier density.

Source: Physical Review Letters

DOI: 10.1103/physrevlett.111.096601