Dissipative dynamics of coupled quantum dots under quantum measurement

TL;DR

This paper investigates how including higher order interactions in the dissipative dynamics model of coupled quantum dots leads to more accurate, asymmetric occupation probabilities, highlighting their importance in qubit operation.

Contribution

It introduces a refined theoretical approach that incorporates higher order interactions, correcting previous unphysical assumptions in quantum dot occupation probabilities.

Findings

Higher order interactions cause asymmetric occupation probabilities in non-identical quantum dots.

Neglecting higher order terms results in unphysical uniform occupation predictions.

Including these terms significantly impacts qubit operation understanding.

Abstract

We have studied the dissipative dynamics of a solid-state qubit with an extra electron confined to either one of two coupled quantum dots. Previous theoretical work based on Bloch-type rate equations gave an unphysical uniform occupation probability of the electron in the quantum dots even for non-identical dots. We show that this is due to neglecting higher order interactions in the analysis. By including higher order terms, we obtain expected asymmetric occupation probabilities for non-identical dots. Our work demonstrates that the high order interaction terms can lead to important qualitative impacts on the operation of the qubit.