Observation of quantum-Hall effect in gated epitaxial graphene grown on SiC (0001)

TL;DR

This paper reports the observation of the quantum-Hall effect in gated epitaxial graphene grown on SiC (0001), demonstrating preserved electrical properties and quantum phenomena at low temperatures.

Contribution

It introduces a method to create a high-k gate stack on epitaxial graphene without degrading its electrical properties and observes quantum-Hall effects in this system.

Findings

Quantum-Hall effect observed in gated epitaxial graphene

Electrical properties remain stable after gate stack formation

Pronounced Shubnikov-de Hass oscillations detected

Abstract

Epitaxial graphene films were formed on the Si-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. A high-k gate stack on epitaxial graphene is realized by inserting a fully oxidized nanometer thin aluminum film as a seeding layer followed by an atomic-layer deposition process. The electrical properties of epitaxial graphene films are sustained after gate stack formation without significant degradation. At low temperatures, the quantum-Hall effect in Hall resistance is observed along with pronounced Shubnikov-de Hass oscillations in diagonal magneto-resistance of gated epitaxial graphene on SiC (0001).