Mesoscopic structures and 2D hole systems in fully field effect controlled heterostructures

TL;DR

This paper introduces methods to create high-mobility 2D hole systems and mesoscopic structures in fully field-effect controlled heterostructures, enabling local carrier density tuning and advanced device fabrication.

Contribution

It presents novel techniques for populating high-mobility 2D hole layers and fabricating mesoscopic structures with local control in heterostructures.

Findings

High mobility 2D hole layers achieved with appropriate contact materials.

A simple method for fabricating mesoscopic structures with local density control.

Demonstration of devices utilizing these new fabrication techniques.

Abstract

Two fundamental extensions to the function of previously described fully field effect two-dimensional (2D) electron heterostructures are presented: First, using the same basic heterostructure design of lithographically defined contacts overlain by both an insulating layer and top-gate employed for electron systems, appropriate contact material allows a high mobility 2D hole layer to be populated. Second, a simple method for producing mesoscopic structures in these devices is presented in which small-scale metallic patterns are placed on the heterostructure under the insulating and global gate layers which allows local carrier density tuning via the overlapping gate arrays. Example devices using these generally applicable methods are demonstrated.