459 research outputs found
Possible Excitonic Phase of Graphite in the Quantum Limit State
The in-plane resistivity, Hall resistivity and magnetization of graphite were
investigated in pulsed magnetic fields applied along the \textit{c}-axis. The
Hall resistivity approaches zero at around 53 T where the in-plane and
out-of-plane resistivities steeply decrease. The differential magnetization
also shows an anomaly at around this field with a similar amplitude compared to
that of de Haas-van Alphen oscillations at lower fields. This transition field
appears insensitive to disorder, but reduces with doping holes. These results
suggest the realization of the quantum limit states above 53 T. As a plausible
explanation for the observed gapped out-of-plane conduction above 53 T, the
emergence of the excitonic BCS-like state in graphite is proposed.Comment: 15 pages, 6 figures, to be published in J. Phys. Soc. Jp
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