Shot noise generated by graphene p–n junctions in the quantum Hall effect regime
説明
<jats:title>Abstract</jats:title><jats:p>Graphene offers a unique system to investigate transport of Dirac Fermions at <jats:italic>p</jats:italic>–<jats:italic>n</jats:italic> junctions. In a magnetic field, combination of quantum Hall physics and the characteristic transport across <jats:italic>p</jats:italic>–<jats:italic>n</jats:italic> junctions leads to a fractionally quantized conductance associated with the mixing of electron-like and hole-like modes and their subsequent partitioning. The mixing and partitioning suggest that a <jats:italic>p</jats:italic>–<jats:italic>n</jats:italic> junction could be used as an electronic beam splitter. Here we report the shot noise study of the mode-mixing process and demonstrate the crucial role of the <jats:italic>p</jats:italic>–<jats:italic>n</jats:italic> junction length. For short <jats:italic>p</jats:italic>–<jats:italic>n</jats:italic> junctions, the amplitude of the noise is consistent with an electronic beam-splitter behaviour, whereas, for longer <jats:italic>p</jats:italic>–<jats:italic>n</jats:italic> junctions, it is reduced by the energy relaxation. Remarkably, the relaxation length is much larger than typical size of mesoscopic devices, encouraging using graphene for electron quantum optics and quantum information processing.</jats:p>
収録刊行物
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- Nature Communications
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Nature Communications 6 (1), 2015-09-04
Springer Science and Business Media LLC