Measurement of the nonadiabatically-induced coherent time evolution of a single-electron wavefunction in a surface acoustic wave dynamic quantum dot

ORAL

Abstract

Observation of coherent single-electron dynamics is severely limited by experimental bandwidth. We present a method to overcome this using moving quantum dots defined by surface acoustic waves. Each dot holds a single electron, and travels through a static potential landscape. When the dot moves abruptly between regions of different confinement, the electron is excited into a superposition of states, and oscillates unitarily from side to side. These oscillations are measured almost non-invasively, by allowing a small amount of tunnelling out of the dot each time the wavefunction approaches a tunnel barrier. We have modelled this in detail by solving the single-particle time-dependent Schr\"odinger equation for a realistic potential, and find good agreement between the measurements and the simulations.

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Authors

  • Adam Thorn

    • University of Cambridge, UK
    • Cavendish Laboratory

  • Masaya Kataoka

    • University of Cambridge, UK

  • Michael Astley

    • University of Cambridge, UK

  • Daniel Oi

    • University of Strathclyde, UK

  • C. H. W. Barnes

    • University of Cambridge, UK
    • University of Cambridge

  • Chris Ford

    • University of Cambridge, UK

  • Dave Anderson

    • University of Cambridge, UK
    • Cavendish Laboratory

  • Geb Jones

    • University of Cambridge, UK
    • Cavendish Laboratory

  • I. Farrer

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

  • D.A. Ritchie

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

  • M. Pepper

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