Engineering electron wavefunctions in asymmetrically confined quasi one-dimensional structures

TL;DR

This paper investigates electron transport in asymmetrically confined quasi-one-dimensional GaAs/AlGaAs quantum wires, revealing anticrossing phenomena of energy levels and the formation of double electron rows influenced by potential asymmetry and inhomogeneity.

Contribution

It demonstrates how asymmetric confinement potentials affect electron energy levels and wavefunctions, including anticrossing behavior and double row formation, advancing understanding of quantum wire manipulation.

Findings

Anticrossing of ground and first excited states observed.

Double electron rows form correlating with anticrossing events.

Inhomogeneity influences the energy level behavior.

Abstract

We present results on electron transport in quasi-one dimensional (1D) quantum wires in GaAs/AlGaAs heterostructures obtained using an asymmetric confinement potential. The variation of the energy levels of the spatially quantized states is followed from strong confinement through weak confinement to the onset of two-dimensionality. An anticrossing of the initial ground and first excited states is found as the asymmetry of the potential is varied giving rise to two anticrossing events which occur on either side of symmetric confinement. We present results analysing this behaviour and showing how it can be affected by the inhomogeneity in background potential. The use of an enhanced source-drain voltage to alter the energy levels is shown to be a significant validation of the analysis by showing the formation of double rows of electrons which correlate with the anticrossing.