2019/10/31 by Huichao Xu, Feixiang Xu, Thomas Theurer +5 · 1 citation
Computer Science · Physics and Astronomy · #Coherence (philosophical gambling strategy) #Coherence length #Coherence theory #Computer science #Degree of coherence #Detector #Open quantum system #Operator (biology) #Optics #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum imaging #Quantum mechanics #Quantum sensor #Quantum technology #Random lasers and scattering media #quant-ph
paper · pdf · doi:10.1103/physrevlett.125.060404
published as Phys. Rev. Lett. 125, 060404 (2020)
openalex publication_date 2020/08/05 · arxiv created 2020/09/29 · arxiv updated 2020/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 of the detector in different configurations. The reconstructed positive-operator-valued measures 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.