Optimally controlled quantum discrimination and estimation

TL;DR

This paper develops an optimal control framework to enhance quantum discrimination and estimation, demonstrating improved performance and stability in noisy environments, significantly extending the effective measurement time beyond decoherence limits.

Contribution

It introduces a novel optimal control approach to quantum discrimination and estimation, improving distinguishability and stability under noise conditions.

Findings

Increased quantum state distinguishability using tailored pulses.

Stabilization of maximum distinguishability beyond decoherence time.

Enhanced performance in magnetic field estimation under noise.

Abstract

Quantum discrimination and estimation are pivotal for many quantum technologies, and their performance depends on the optimal choice of probe state and measurement. Here we show that their performance can be further improved by suitably tailoring the pulses that make up the interferometer. Developing an optimal control framework and applying it to the discrimination and estimation of a magnetic field in the presence of noise, we find an increase in the overall achievable state distinguishability. Moreover, the maximum distinguishability can be stabilized for times that are more than an order of magnitude longer than the decoherence time.