Engineering electron wavefunctions in asymmetrically confined quasi one-dimensional structures
S. Kumar, M. Pepper, H. Montagu, D. Ritchie, I. Farrer, J. Griffiths, G. Jones
Abstract
We present results on electron transport in quasi-one dimensional 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 analyzing this behavior 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.