Interplay and optimization of decoherence mechanisms in the optical control of spin quantum bits implemented on a semiconductor quantum dot

TL;DR

This paper investigates how environmental factors affect optical spin control in semiconductor quantum dots, analyzing decoherence sources and optimizing parameters to achieve high-fidelity qubit operations.

Contribution

It provides a detailed analysis of decoherence mechanisms and offers optimization strategies for high-precision optical spin control in quantum dots.

Findings

Total error can be reduced to 10^{-4} with optimal parameters

Decoherence from lattice response significantly impacts spin control fidelity

Finite trion lifetime and off-resonant excitations are key error sources

Abstract

We study the influence of the environment on an optically induced rotation of a single electron spin in a charged semiconductor quantum dot. We analyze the decoherence mechanisms resulting from the dynamical lattice response to the charge evolution induced in a trion-based optical spin control scheme. Moreover, we study the effect of the finite trion lifetime and of the imperfections of the unitary evolution such as off-resonant excitations and the nonadiabaticity of the driving. We calculate the total error of the operation on a spin-based qubit in an InAs/GaAs quantum dot system and discuss possible optimization against the different contributions. We indicate the parameters which allow for coherent control of the spin with a single qubit gate error as low as $10^{-4}$.