High mobility two-dimensional hole system on hydrogen-terminated silicon (111) surfaces

TL;DR

This paper reports the creation of a high-mobility two-dimensional hole system on hydrogen-terminated silicon (111) surfaces, demonstrating quantum Hall effects and tunable spin splitting at very low temperatures.

Contribution

It introduces a novel method to induce a 2DHS on atomically flat Si(111) surfaces with high mobility and tunable spin properties, advancing silicon-based quantum device research.

Findings

Hole densities up to 7.5×10^{11} cm^{-2} achieved.

Peak hole mobility about 10^4 cm^2/Vs at 70 mK.

Observation of quantum Hall effect and tunable spin splitting.

Abstract

We have realized a two-dimensional hole system (2DHS), in which the 2DHS is induced at an atomically flat hydrogen-terminated Si(111) surface by a negative gate voltage applied across a vacuum cavity. Hole densities up to $7.5\times10^{11}$ cm$^{-2}$ are obtained, and the peak hole mobility is about $10^4$ cm$^2$/Vs at 70 mK. The quantum Hall effect is observed. Shubnikov-de Haas oscillations show a beating pattern due to the spin-orbit effects, and the inferred zero-field spin splitting can be tuned by the gate voltage.