Efficiency of optimal control for noisy spin qubits in diamond

TL;DR

This paper explores how environmental noise characteristics influence the design of optimal control pulses for spin qubits in diamond, providing strategies and experimental validation to improve quantum control under realistic noise conditions.

Contribution

It investigates the impact of noise correlation time on control pulse shape and offers optimized strategies validated through experiments for realistic quantum systems.

Findings

Control pulse shape depends on environmental noise correlation time

Constraints and optimization options significantly affect control outcomes

Experimental validation confirms the feasibility of optimized pulses

Abstract

Decoherence is a major challenge for quantum technologies. A way to mitigate its negative impact is by employing quantum optimal control. The decoherence dynamics varies significantly based on the characteristics of the surrounding environment of qubits, consequently affecting the outcome of the control optimization. In this work, we investigate the dependence of the shape of a spin inversion control pulse on the correlation time of the environment noise. Furthermore, we analyze the effects of constraints and optimization options on the optimization outcome and identify a set of strategies that improve the optimization performance. Finally, we present an experimental realization of the numerically-optimized pulses validating the optimization feasibility. Our work serves as a generic yet essential guide to implementing optimal control in the presence of realistic noise, e.g., in nitrogen-vacancy centers in diamond.