The zero-energy state in graphene in a high magnetic field

Abstract

The fate of the charge-neutral Dirac point in graphene in a high magnetic field $H$ has been investigated at low temperatures ($T\sim$ 0.3 K). In samples with small $V_0$ (the gate voltage needed to access the Dirac point), the resistance $R_0$ at the Dirac point diverges steeply with $H$, signalling a crossover to an insulating state in intense field. The approach to the insulating state is highly unusual. Despite the steep divergence in $R_0$, the profile of $R_0$ vs. $T$ in fixed $H$ saturates to a $T$-independent value below 2 K, consistent with charge carrying gapless excitations.

4 pages, 4 figures. Four new sub-figures have been added. Text expanded to discuss data from more samples

References in corpus (6)

• Electric Field Effect in Atomically Thin Carbon Films
• Two Dimensional Atomic Crystals
• Measurement of Scattering Rate and Minimum Conductivity in Graphene
• Dissipative Quantum Hall Effect in Graphene near the Dirac Point
• Order from Disorder in Graphene Quantum Hall Ferromagnet
• Spontaneous Symmetry Breaking and Quantum Hall Effect in Graphene

Cited by in corpus (11)

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• Dynamics in the quantum Hall effect and the phase diagram of graphene
• Edge states on graphene ribbon in magnetic field: interplay between Dirac and ferromagnetic-like gaps
• The enigma of the nu=0 quantum Hall effect in graphene
• Toward theory of quantum Hall effect in graphene
• Edge states in graphene in magnetic fields -- a speciality of the edge mode embedded in the n=0 Landau band
• Splitting of critical energies in the $n$=0 Landau level of graphene
• Neutral triplet Collective Mode as a new decay channel in Graphite