Dephasing in a quantum dot due to coupling with a quantum point contact

TL;DR

This paper investigates how charge fluctuations in a biased quantum point contact cause dephasing of an electron in a quantum dot, revealing a relationship with shot-noise that differs from traditional suppression patterns.

Contribution

It demonstrates that dephasing rate depends on bias and temperature similarly to shot-noise but does not follow the expected suppression pattern, providing new insights into quantum dot decoherence.

Findings

Dephasing rate correlates with shot-noise in the quantum point contact.

Dephasing does not follow the |t|^2(1-|t|^2) suppression pattern.

Temperature and bias influence dephasing similarly to shot-noise.

Abstract

We consider the dephasing of an one-electron state in a quantum dot due to charge fluctuations in a biased quantum point contact coupled to the dot capacitively. The contribution to the dephasing rate due to the bias depends on temperature and bias in the same way as shot-noise in the point contact at zero frequency, but do not follow the |t|^2(1-|t|^2) suppression.