Transport phenomena in a gate selective vertical double quantum dot

POSTER

Abstract

Certain proposals for a spin qubit require gate control of the position of an electron in a selected 2DEG composition. Conventionally this depends upon patterning of both top and backgates on to a substrate to a precision of within a few nanometres, a non-trivial process. Here we report an attempt to control relative population of two vertical quantum dots using only surface gates. The dots are defined using electrostatic surface gates on a double GaAs quantum well structure with a 7nm barrier. An additional top gate is used to control electron density and coupling between the two dots and hence the dominant transport path. In the crossover regime we observe Fano resonances and charge detection signatures in the conductance through the double dot. This is the first step towards control of the position of a single electron in a vertical double quantum dot composed of different semiconductor materials using only surface gates.

Authors

  • Victoria Russell

    • University of Cambridge \& Toshiba Research Europe Ltd.
    • University of Cambridge \& Toshiba Reseacrh Europe Limited

  • Simon Chorley

    • University of Cambridge

  • Francois Sfigakis

    • University of Cambridge

  • Stuart Holmes

    • Toshiba Research Europe Ltd.
    • Toshiba Research Europe Limited

  • David Anderson

    • University of Cambridge
    • Cavendish Laboratory, University of Cambridge, UK

  • Geb Jones

    • University of Cambridge
    • Cavendish Laboratory, University of Cambridge, UK

  • Crispin Barnes

    • University of Cambridge
    • Cavendish Laboratory, University of Cambridge, UK

  • Ian Farrer

    • Cavendish Laboratory, University of Cambridge
    • University of Cambridge
    • Cavendish Laboratory, University of Cambridge, UK

  • Charles Smith

    • University of Cambridge

  • David Ritchie

    • University of Cambridge
    • Universiy of Cambridge
    • Cavendish Laboratory, University of Cambridge
    • Cavendish Laboratory, University of Cambridge, UK

  • Michael Pepper

    • University of Cambridge