Experimental quantification of coherence of a tunable quantum detector

TL;DR

This paper experimentally quantifies the coherence detection ability of a quantum optical detector using resource theory, improved tomography algorithms, and POVM reconstruction, providing a rigorous performance evaluation from a quantum resource perspective.

Contribution

It introduces an experimental approach to quantify quantum coherence detection in detectors using resource theory and improved tomography methods.

Findings

Reconstructed POVMs of the detector in various configurations.

Quantified the detector's coherence detection capability with computable measures.

Provided the first experimental resource-theoretic analysis of quantum measurements.

Abstract

Quantum coherence is a fundamental resource that quantum technologies exploit to achieve performance beyond that of classical devices. A necessary prerequisite to achieve this advantage is the ability of measurement devices to detect coherence from the measurement statistics. Based on a recently developed resource theory of quantum operations, here we quantify experimentally the ability of a typical quantum-optical detector, the weak-field homodyne detector, to detect coherence. We derive an improved algorithm for quantum detector tomography and apply it to reconstruct the positive-operator-valued measures (POVMs) of the detector in different configurations. The reconstructed POVMs are then employed to evaluate how well the detector can detect coherence using two computable measures. As the first experimental investigation of quantum measurements from a resource theoretical perspective, our work sheds new light on the rigorous evaluation of the performance of a quantum measurement apparatus.