Transport spectroscopy of singlet-triplet quantum dot states coupled to electronic cavities

TL;DR

This paper investigates how an electronic cavity influences inelastic singlet-triplet transport in a quantum dot, confirming experimental signatures with theoretical modeling and highlighting the cavity's role in cotunneling processes.

Contribution

It demonstrates the impact of a coupled electronic cavity on singlet-triplet transport in quantum dots, combining experimental observations with a theoretical model that includes lead coupling effects.

Findings

Transport signatures match theoretical predictions

Cavity affects higher-order cotunneling processes

Model captures interplay between cavity and dot states

Abstract

A strong coupling between an electronic cavity and a quantum dot has been recently demonstrated [Phys. Rev. Lett. 115, 166603 (2015)] and described in a comprehensive theoretical framework [Phys. Rev. B 96, 235431 (2017)]. Here, we focus on the signatures that demonstrate the cavity's impact on inelastic singlet-triplet transport through the dot. We find the same transport signatures in the experiment as predicted by the model that describes the coupled dot--cavity system. Interestingly, a lowest-order treatement of the coupling to the electronic leads on top of an exact diagonalisation of the dot-cavity system is sufficient to highlight the interplay between the cavity and the higher-order inelastic singlet-triplet cotunneling.