Interaction Determined Electron Energy Levels in One-Dimension

ORAL

Abstract

We have investigated electron transport in a quasi-one dimensional electron gas in the GaAs-AlGaAs heterostructure designed so that the confinement potential can be progressively weakened. This causes the energy levels to decrease in energy relative to each other, however this decrease occurs at different rates, a feature attributed to the energy being determined by both confinement and the electron-electron repulsion which varies with the shape of the wavefunction. It is found that the initial ground state crosses the higher levels so resulting in missing plateaux of quantised conductance. A change in the nature of the ground state to a more extended form causes an increase in the capacitance between the confining gates and the electrons. Both crossings and anti-crossings of the levels are found and these will be discussed along with other consequences of the form of the level interactions. The effects of level crossing on the spin dependent 0.7 structure will be presented.

Authors

  • Michael Pepper

    University College London, Department of Electronic and Electrical Engineering, University College London

  • Sanjeev Kumar

    University College London

  • Kalarikad Thomas

    University College London

  • Luke Smith

    Cavendish Laboratory, University of Cambridge

  • Graham Creeth

    University College London

  • Ian Farrer

    Cavendish Laboratory, University of Cambridge

  • David Ritchie

    University of Cambridge, Cavendish Laboratory, University of Cambridge

  • Geraint Jones

    University of Cambridge, Cavendish Laboratory, University of Cambridge

  • Griffiths Jonathan

    University of Cambridge, Cavendish Laboratory, University of Cambridge