Field effect induced mesoscopic devices in depleted two dimensional electron systems

TL;DR

This paper introduces a novel method for defining mesoscopic devices in 2DES by globally depleting the electron system and locally screening with nanoscale gates, simplifying circuit design and enabling complex quantum structures.

Contribution

The study demonstrates a new approach to device fabrication in 2DES using global depletion and local screening, reducing gate complexity and enabling advanced quantum device architectures.

Findings

Successful control of carrier properties via geometry and voltages

Observation of electrostatic, dynamic, and coherent effects

Potential for simplified complex quantum circuits

Abstract

Nanoelectronic devices embedded in the two-dimensional electron system (2DES) of a GaAs/AlGaAs heterostructure enable a large variety of applications from fundamental research to high speed transistors. Electrical circuits are thereby commonly defined by creating barriers for carriers by selective depletion of a pre-existing 2DES. Here we explore an alternative approach: we deplete the 2DES globally by applying a negative voltage to a global top gate and screen the electric field of the top gate only locally using nanoscale gates placed on the wafer surface between the plane of the 2DES and the top gate. Free carriers are located beneath the screen gates and their properties can be controlled by means of geometry and applied voltages. This method promises considerable advantages for the definition of complex circuits by the electric field effect as it allows to reduce the number of gates and simplify gate geometries. Examples are carrier systems with ring topology or large arrays of quantum dots. Here, we present a first exploration of this method pursuing field effect, Hall effect and Aharonov-Bohm measurements to study electrostatic, dynamic and coherent properties.