Single-electron coherence: finite temperature versus pure dephasing

TL;DR

This paper compares the effects of finite temperature and pure dephasing on single-electron quantum states, revealing that temperature preserves coherence while dephasing suppresses antibunching, with implications for quantum electronic applications.

Contribution

It demonstrates that finite temperature does not impair electron coherence, unlike pure dephasing, and clarifies the distinct impacts of these mixedness sources on quantum states.

Findings

Finite temperature preserves electron coherence and antibunching.

Pure dephasing suppresses antibunching in single-electron states.

Shot noise is reduced at finite temperature but unaffected by pure dephasing.

Abstract

We analyze a coherent injection of single electrons on top of the Fermi sea in two situations, at finite-temperature and in presence of pure dephasing. Both finite-temperature and pure dephasing change the property of the injected quantum states from pure to mixed. However, we show that the temperature-induced mixedness does not alter the coherence properties of these single-electronic states. In particular two such mixed states exhibit perfect antibunching while colliding at an electronic wave splitter. This is in striking difference with the dephasing-induced mixedness which suppresses antibunching. On the contrary, a single-particle shot noise is suppressed at finite temperatures but is not affected by pure dephasing. This work therefore extends the investigation of the coherence properties of single-electronic states to the case of mixed states and clarifies the difference between different types of mixedness.