Correlation of Conductance Measurements from a Quantum Dot with Three Terminals

ORAL

Abstract

We have measured the differential conductance of a quantum dot coupled by three tunable tunneling barriers to three terminals. The quantum dot is formed by laterally constricting a two-dimensional electron gas (2DEG) in an Al$_{x}$Ga$_{1-x}$As/GaAs heterostructure with Schottky split-gates. The advantage to performing conductance measurements on a quantum dot with three leads is that we are able to directly measure information about the individual tunneling barriers and determine how the states interact with the leads. At a base temperature of 250mK, we have observed new phenomena not previously reported from three-terminal, mesoscopic experiments. These effects include conductance peak suppression in the nonlinear bias regime and the simultaneous coupling of two different states to two separate leads.

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Authors

  • Ryan Toonen

    Department of Electrical and Computer Engineering, University of Wisconsin at Madison

  • Marta Prada

    School of Electronic and Electrical Engineering, University of Leeds

  • H. Qin

    Department of Electrical and Computer Engineering, University of Wisconsin at Madison

  • Andreas Huettel

    Sektion Physik, Ludwig-Maximilians-Universitaet

  • Srijit Goswami

  • M.A. Eriksson

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin at Madison, Department of Physics, University of Wisconsin - Madison, University of Wisconsin-Madison

  • Robert Blick

    Department of Electrical and Computer Engineering, University of Wisconsin at Madison, Department of Electrical and Computer Engineering, University of Wisconsin-Madison

  • Daniel van der Weide

    Department of Electrical and Computer Engineering, University of Wisconsin at Madison, University of Wisconsin-Madison

  • Karl Eberl

    Max-Planck-Institut fuer Festkoerperforschung Stuttgart