Phase measurement of photon-assisted tunneling through a quantum dot

TL;DR

This paper proposes a method to measure the phase of photon-assisted tunneling in a quantum dot using Aharonov-Bohm interference, revealing coherent photon absorption and emission processes.

Contribution

It introduces an extension to existing interference experiments by applying an ac voltage, enabling phase measurement of photon-assisted tunneling in quantum dots.

Findings

Predicted additional structure in Aharonov-Bohm signals due to ac voltage

Proposed experimental verification of coherent photon absorption

Enhanced understanding of photon-assisted tunneling mechanisms

Abstract

Recent double-slit interference experiments have demonstrated the possibility of probing the phase of the complex transmission coefficient of a quantum dot via the Aharonov-Bohm effect. We propose an extension of these experiments: an ac voltage imposed on the side gate with the concomitant photonic sidebands leads to additional structure both in the amplitude and in the phase of the Aharonov-Bohm signal. Observation of these effects would be a definitive proof of coherent absorption and reemission of photons from the ac source.