Self-consistent Schrödinger-Poisson simulation of Quantum Point Contacts with varying top gate shapes

Quantum Point Contacts (QPC) are essential components in many quantum nanoelectronics, due to the control they provide in quantum channels.¹ Their operation has only been examined before using a combination of numerical and analytical techniques, or using only a single device. We present herein the results of three-dimensional self-consistent Schrödinger-Poisson simulations for different designs of the surface gates that define the shape of the electron density distribution in the 2DEG under a GaAs/AlGaAs heterostructure. Each design is also examined at varying dimensions. The parameters used for the simulations were extracted from experiments. The method used to extract the simulated voltage at which the last conductance channel in the experimental QPC is expected to turn-off (pinch-off voltage) is also presented. A very good agreement between the two was achieved with the parameters used throughout our work.

¹ Bäuerle, C., Christian Glattli, D., Meunier, T., Portier, F., Roche, P., Roulleau, P., Takada, S., & Waintal, X. (2018). Coherent control of single electrons: A review of current progress. Reports on Progress in Physics, 81(5).