Time-resolved detection of single-electron interference

TL;DR

This paper reports real-time detection of single-electron interference in a quantum dot interferometer, revealing high visibility and the impact of back-action-induced decoherence due to quantum point contact radiation.

Contribution

It demonstrates time-resolved measurement of single-electron interference with near-unity visibility and analyzes back-action effects causing decoherence.

Findings

High-visibility single-electron interference observed.

Back-action from quantum point contact causes decoherence.

Radiation emission drives non-coherent electronic transitions.

Abstract

We demonstrate real-time detection of self-interfering electrons in a double quantum dot embedded in an Aharonov-Bohm interferometer, with visibility approaching unity. We use a quantum point contact as a charge detector to perform time-resolved measurements of single-electron tunneling. With increased bias voltage, the quantum point contact exerts a back-action on the interferometer leading to decoherence. We attribute this to emission of radiation from the quantum point contact, which drives non-coherent electronic transitions in the quantum dots.