Hydrodynamic pumping of a quantum Fermi liquid in a semiconductor heterostructure

TL;DR

This paper investigates a hydrodynamic pumping mechanism in a Fermi liquid within a semiconductor heterostructure, demonstrating how electron-electron interactions can induce carrier currents and voltages through a novel quantum effect.

Contribution

It introduces a new quantum hydrodynamic pumping mechanism driven by electron-electron interactions, supported by experimental observations and theoretical Boltzmann equation analysis.

Findings

Electron beam induces measurable current or voltage signals.

Theoretical model shows positive potential near injected electrons due to Coulomb interactions.

Pumping mechanism differs from classical Bernoulli effects.

Abstract

We describe both experimentally and theoretically a hydrodynamic pumping mechanism in a Fermi liquid, arising from electron-electron interaction. An electron beam sweeping past an aperture is observed to pump carriers from this aperture. Experimentally, the pumping effect induces a current in the lead connected to the aperture, or induces a voltage signal corresponding to carrier extraction from the lead. Different geometries display the effect, and this work discusses one experimental geometry in detail. Theoretically, the solution of the Boltzmann equation, including an electron-electron collision integral, shows that the potential induced by injected electrons becomes positive in the regions nearby the main stream of injected electrons. Thus, the repulsive Coulomb interaction leads to an attractive, pumping force in the Fermi liquid. The pumping mechanism here described is shown to be qualitatively different from the Bernoulli pumping effect in classical liquids.