Conductance Quantization in Schottky-gated Si/SiGe Quantum Point Contacts

TL;DR

This paper reports on the fabrication and characterization of Si/SiGe quantum point contacts, demonstrating conductance quantization at zero magnetic field and low temperature, indicating transport through non-degenerate 1D modes.

Contribution

It introduces a method to fabricate Schottky-gated Si/SiGe QPCs and observes conductance quantization without spin or valley degeneracy.

Findings

Conductance quantization observed at e^2/h units

Transport occurs through non-degenerate 1D modes

QPCs operate at low temperature and zero magnetic field

Abstract

We report on the fabrication and electronic transport characterisation of Schottky-gated strongly confined Si/SiGe quantum point contacts (QPC). At zero magnetic field and T=450mK the QPC conductance as a function of gate voltage shows a quantization in units of e^2/h, indicative of transport through 1D modes which appear to lack both spin and valley degeneracy.