Lateral tunneling through the controlled barrier between edge channels in a two-dimentional electron system

TL;DR

This paper investigates lateral tunneling between edge channels in a two-dimensional electron system with a gate-controlled barrier, revealing asymmetric current-voltage characteristics and linear dependencies on gate voltage and magnetic field.

Contribution

It demonstrates how a gate-induced barrier affects tunneling between edge channels and characterizes the barrier's dependence on external parameters.

Findings

Current-voltage characteristic is strongly asymmetric.

Barrier height depends linearly on gate voltage and magnetic field.

Tunneling occurs between outermost edge channels.

Abstract

We study the lateral tunneling through the gate-voltage-controlled barrier, which arises as a result of partial elimination of the donor layer of a heterostructure along a fine strip using an atomic force microscope, between edge channels at the depletion-induced edges of a gated two-dimensional electron system. For a sufficiently high barrier a typical current-voltage characteristic is found to be strongly asymmetric and include, apart from a positive tunneling branch, the negative branch that corresponds to the current overflowing the barrier. We establish the barrier height depends linearly on both gate voltage and magnetic field and we describe the data in terms of electron tunneling between the outermost edge channels.