Stopping electrons with radio-frequency pulses in the quantum Hall regime

TL;DR

This paper demonstrates that radio-frequency pulses can dynamically stop charge pulses in quantum Hall edge states, revealing new control methods for electron flow in quantum systems.

Contribution

It introduces a method to stop and manipulate charge pulses using RF excitations in quantum Hall edge states, a novel approach for quantum electronic control.

Findings

Fast RF gate voltage changes can halt charge pulse propagation.

Stopping is linked to vanishing bulk state velocity and Landau level properties.

Potential for new charge pulse control and switching in quantum Hall systems.

Abstract

Most functionalities of modern electronic circuits rely on the possibility to modify the path fol- lowed by the electrons using, e.g. field effect transistors. Here we discuss the interplay between the modification of this path and the quantum dynamics of the electronic flow. Specifically, we study the propagation of charge pulses through the edge states of a two-dimensional electron gas in the quantum Hall regime. By sending radio-frequency (RF) excitations on a top gate capacitively coupled to the electron gas, we manipulate these edge state dynamically. We find that a fast RF change of the gate voltage can stop the propagation of the charge pulse inside the sample. This effect is intimately linked to the vanishing velocity of bulk states in the quantum Hall regime and the peculiar connection between momentum and transverse confinement of Landau levels. Our findings suggest new possibilities for stopping, releasing and switching the trajectory of charge pulses in quantum Hall systems.