Electron and electron-hole quasiparticle states in a driven quantum contact

TL;DR

This paper investigates the many-body electronic states generated by a time-dependent voltage in a mesoscopic contact, identifying quasiparticle excitations and experimentally confirming their time dependence through noise measurements.

Contribution

It provides a theoretical framework for expressing the many-body state in terms of single-electron and electron-hole quasiparticles and experimentally verifies these predictions using noise correlation measurements.

Findings

Electronic states are composed of quasiparticles with specific amplitudes and probabilities.

Time dependence of electronic states matches theoretical predictions.

Current noise power reveals the overlap of electron wave packets.

Abstract

We study the many-body electronic state created by a time-dependent drive of a mesoscopic contact. The many-body state is expressed manifestly in terms of single-electron and electron-hole quasiparticle excitations with the amplitudes and probabilities of creation which depend on the details of the applied voltage. We experimentally probe the time dependence of the constituent electronic states by using an analog of the optical Hong-Ou-Mandel correlation experiment where electrons emitted from the terminals with a relative time delay collide at the contact. The electron wave packet overlap is directly related to the current noise power in the contact. We have confirmed the time dependence of the electronic states predicted theoretically by measurements of the current noise power in a tunnel junction under harmonic excitation.