Projected Optimal Sensors from Operator Orbits

TL;DR

This paper unifies various quantum sensor models using operator algebra, demonstrating how operator orbits influence sensitivity scaling and designing sensors with beyond-shot-noise performance and favorable Fisher information scaling.

Contribution

It introduces a unified operator algebra framework for quantum sensors, enabling the design of sensors with enhanced sensitivity and robustness against decoherence.

Findings

Operator orbits determine sensitivity scaling.

Designed sensors outperform shot-noise limits.

Fisher information scales favorably with decoherence.

Abstract

We unify Ramsey, twist-untwist, and random quantum sensors using operator algebra and account for the Fisher scaling of various sensor designs. We illustrate how the operator orbits associated with state preparation inform the scaling of the sensitivity with the number of subsystems. Using our unified model, we design a novel set of sensors in which a projected ensemble of quantum states exhibits beyond-shot-noise metrological performance. We also show favorable scaling of Fisher information with decoherence models and loss of particles.