Geometric interference observed in a high-mobility graphene ring

ORAL

Abstract

We observe a strong quantum interference pattern in low-temperature resistance measurements of a ring-shaped h-BN/graphene/h-BN~pn-junction device. The graphene has a mobility of 200,000 cm$^{\mathrm{2}}$/Vs at a concentration of 10$^{\mathrm{10}}$~cm$^{\mathrm{-2}}$. The ring is placed on top of a pair of buried gates that allow the left and right halves of the ring to be independently gated, forming gate-voltage quadrants for different carrier types across the ring. At low-temperatures, 400~mK~to 10 K, the measured resistance as a function of gate voltage exhibits a~strong interference pattern. The peaks and valleys are much larger in amplitude than the relatively weak~Aharonov-Bohm oscillations observed when the magnetic field is swept at fixed gate voltage. The interference is robust and remains in the presence of moderate magnetic fields (on the order of 0.1~T). Tight-binding quantum transport calculations of the device geometry show a similar interference pattern, and systematic modeling indicates that the interference pattern arises from spatial quantization in the device.~

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Authors

  • Curt Richter

    The National Institute Of Standards And Technology, The National Institute of Standards and Technology

  • Son T. Le

    The National Institute Of Standards And Technology, The National Institute of Standards and Technology

  • Joseph Hagmann

    The National Institute Of Standards And Technology, The National Institute of Standards and Technology, NIST - Natl Inst of Stds & Tech

  • Christopher Gutierrez

    The National Institute Of Standards And Technology, NIST, Center for Nanoscale Science and Technology, NIST / Maryland NanoCenter, University of Maryland, College Park

  • Guangjun Cheng

    The National Institute Of Standards And Technology, The National Institute of Standards and Technology

  • Nikolai Klimov

    The National Institute Of Standards And Technology, The National Institute of Standards and Technology

  • Angela R. Hight Walker

    The National Institute Of Standards And Technology, NIST - Natl Inst of Stds & Tech, National Institute of Standards and Technology, The National Institute of Standards and Technology, Engineering Physics Division, National Institute of Standards and Technology

  • Joseph Stroscio

    Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD 20899, USA, The National Institute Of Standards And Technology

  • David Newell

    The National Institute Of Standards And Technology, The National Institute of Standards and Technology

  • Ji ung Lee

    Suny Polytechnic, State Univ of NY - Polytechnic Institute

  • Jun Yan

    University of Massachusetts at Amherst, Univ of Mass - Amherst, Department of Physics, UMass Amherst, Department of Physics