Performance advantage of protective quantum measurements

TL;DR

This paper compares protective quantum measurements with standard projective measurements, demonstrating that protective measurements can significantly reduce uncertainty in expectation value estimation, thus offering a performance advantage.

Contribution

It provides a quantitative analysis and explicit expression for the performance difference, highlighting the advantages of protective measurements over traditional methods.

Findings

Protective measurements reduce measurement uncertainty.

Explicit formula for relative performance is derived.

Protective measurements outperform projective measurements in certain scenarios.

Abstract

We compare the performance of protective quantum measurements to that of standard projective measurements. Performance is quantified in terms of the uncertainty in the measured expectation value. We derive an expression for the relative performance of these two types of quantum measurements and show explicitly that protective measurements can provide a significant performance advantage over standard projective measurements.