Fractional quantum conductance staircase of edge hole channels in silicon quantum wells

TL;DR

This paper reports the observation of fractional quantum conductance steps in edge hole channels within ultra-narrow silicon quantum wells, revealing fractional plateaus in the quantum conductance staircase.

Contribution

It demonstrates the fractional quantum conductance in silicon quantum wells caused by edge hole channels, a novel observation in silicon-based nanostructures.

Findings

Observation of fractional quantum conductance plateaus

Correlation of fractional steps with odd and even fractions

Identification of edge hole channels in silicon quantum wells

Abstract

We present the findings for the fractional quantum conductance of holes that is caused by the edge channels in the silicon nanosandwich prepared within frameworks of the Hall geometry. This nanosandwich represents the ultra-narrow p-type silicon quantum well (Si-QW), 2 nm, confined by the {\delta}-barriers heavily doped with boron on the n-type Si (100) surface. The edge channels in the Si-QW plane are revealed by measuring the longitudinal quantum conductance staircase, Gxx, as a function of the voltage applied to the Hall contacts, Vxy, to a maximum of 4e2/h. In addition to the standard plateau, 2e2/h, the variations of the Vxy voltage appear to exhibit the fractional form of the quantum conductance staircase with the plateaus and steps that bring into correlation respectively with the odd and even fractional values.