Confinement potential in an asymmetrically biased quantum point contact

Two-dimensional Schrodinger and Poisson equations are solved numerically to determine the position of the electron channel and the lateral confinement potential of an asymmetrically biased split-gate quantum point contact (QPC). The conductance of an asymmetrically biased QPC was measured at low temperature, and a change in the widths of conductance plateaus was observed, suggesting that the lateral confinement potential became broad under the asymmetric bias conditions. It is concluded that asymmetric bias affects not only the position of the electron path but also the confinement potential.