Abstract
Most of the functionality of modern electronic circuits relies on the possibility to modify the path followed 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 states 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 possibilities for stopping, releasing, and switching the trajectory of charge pulses in quantum Hall systems.
- Received 28 April 2014
- Revised 16 June 2014
DOI:https://doi.org/10.1103/PhysRevB.90.161305
©2014 American Physical Society