Two Dimensional Electron and Hole Gases at the Surface of Graphite

TL;DR

This paper demonstrates the induction of high-mobility two-dimensional electron and hole gases on graphite surfaces using electric fields, revealing ballistic transport and quantum oscillations, which could impact future electronic device development.

Contribution

It reports the creation of high-quality 2D electron and hole gases on graphite with record mobilities and quantum oscillations, advancing understanding of surface electronic properties.

Findings

High mobilities up to 60,000 cm2/Vs at low temperatures.

Observation of Shubnikov-de Haas oscillations indicating quantum effects.

Ballistic transport over micron scales.

Abstract

We report high-quality two-dimensional (2D) electron and hole gases induced at the surface of graphite by the electric field effect. The 2D carriers reside within a few near-surface atomic layers and exhibit mobilities up to 15,000 and 60,000 cm2/Vs at room and liquid-helium temperatures, respectively. The mobilities imply ballistic transport at micron scale. Pronounced Shubnikov-de Haas oscillations reveal the existence of two types of carries in both 2D electron and hole gases.