Persistent current distributions along a p-n junction in graphene in a magnetic field

Abstract

A p-n junction, induced in graphene by gating, works to contrast the edge states of electrons and holes on each side of it. In a magnetic field those edge states carry two species of persistent current, which are intimately tied to the edge-mode spectra. We study how those persistent currents change along each side of the junction as the Fermi level is varied, with special emphasis on the electron-hole conjugation property of the Dirac electrons. A close look is made into the electromagnetic response of the valence band filled with negative-energy electrons, or the Dirac sea, which as a whole turns out to be electrically inactive while showing intrinsic orbital diamagnetism. Recently, in experiment, it became possible to observe local currents in planar samples by use of a nanoscale magnetometer. The p-n junctions in graphene and related atomic layers, via detection of associated microscopic currents, will be a useful platform for exploring many-body quantum phenomena.

11 pages, 4 figures

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• Chiral tunneling and the Klein paradox in graphene
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Cited by in corpus (1)

• Persistent current and orbital magnetization along a valley-contrasting junction in bilayer graphene in a magnetic field