Phonon-mediated decoherence in triple quantum dot interferometers

TL;DR

This paper explores how phonon-induced decoherence impacts electron transport in a triple quantum dot system, revealing that phonons can lift current blockade by disrupting dark states, with results supported by numerical and analytical methods.

Contribution

It introduces a combined numerical and analytical approach to study phonon-mediated decoherence effects in triple quantum dot interferometers.

Findings

Phonon interactions enable finite current where blockade would occur.

Analytical results agree with numerical simulations.

Decoherence modifies shot noise characteristics.

Abstract

We investigate decoherence in a triple quantum dot in ring configuration in which one dot is coupled to a damped phonon mode, while the other two dots are connected to source and drain, respectively. In the absence of decoherence, single electron transport may get blocked by an electron falling into a superposition decoupled from the drain and known as dark state. Phonon-mediated decoherence affects this superposition and leads to a finite current. We study the current and its shot noise numerically within a master equation approach for the electrons and the dissipative phonon mode. A polaron transformation allows us to obtain a reduced equation for only the dot electrons which provides analytical results in agreement with numerical ones.