Three-level mixing and dark states in transport through quantum dots

TL;DR

This paper theoretically analyzes transport in double quantum dots, revealing how three-level mixing causes current suppression and dark states, with effects depending on bias direction, supported by calculations of current and shot noise.

Contribution

It introduces a theoretical model explaining current suppression and dark states in double quantum dots due to three-level mixing, connecting to experimental observations.

Findings

Current suppression varies with bias direction.

Dark states lead to coherent population trapping.

Theoretical calculations match experimental features.

Abstract

We consider theoretically the transport through the double quantum dot structure of the recent experiment of C. Payette {\it et al.} [Phys. Rev. Lett. {\bf 102}, 026808 (2009)] and calculate stationary current and shotnoise. Three-level mixing gives rise to a pronounced current suppression effect, the character of which charges markedly with bias direction. We discuss these results in connexion with the dark states of coherent population trapping in quantum dots.