Quantum point contact due to Fermi-level pinning and doping profiles in semiconductor nanocolumns

TL;DR

This paper demonstrates how specific doping profiles and surface effects in semiconductor nanocolumns create a quantum point contact, influencing electron transport by forming a saddle-point potential that causes lateral confinement variation.

Contribution

It introduces a novel mechanism where doping and Fermi-level pinning induce a quantum point contact within nanocolumns, supported by analytical quantization energy estimates.

Findings

Formation of saddle-point potential due to doping and Fermi-level pinning

Variation in lateral confinement along the transport direction

Analytical estimation of quantization energies

Abstract

We show that nanoscale doping profiles inside a nanocolumn in combination with Fermi-level pinning at the surface give rise to the formation of a saddle-point in the potential profile. Consequently, the lateral confinement inside the channel varies along the transport direction, yielding an embedded quantum point contact. An analytical estimation of the quantization energies will be given.