Ancilla assisted calibration of a measuring apparatus

Published

June 19, 2012

Author(s)

Alan L. Migdall, Giorgio Brida, L. Ciavarella, Ivo P. Degiovanni, Marco Genovese, M. G. Mingolla, M. G. A. Paris, Fabrizio Piacentini, Sergey Polyakov

Abstract

The rapid development of quantum systems has enabled a wide range of novel and innovative technologies, from quantum information processing to quantum etrology and imaging [113], mainly based on optical systems. Precise characterization techniques of quantum resources, i.e. states [1421], operations [2225] and detectors [2629] play a critical role in development of such technolo- gies. In turn, the most reliable methods for quantum characterization rely on quantum properties of their resources, such as entanglement. Here we present the rst experimental characterization of quantum properties of an unknown detector, the reconstruction of its positive operator-valued measure (POVM), that takes advantage of a quantum resource, i.e. an ancillary state. In our experiment a POVM of a phase-insensitive photon-number-resolving detector is reconstructed with an accuracy that exceeds classical methods, while using no prior information about that detector. This is done by exploiting strong quantum correlations of twin beams generated by a parametric down conversion crystal: one beam is characterized by a quantum tomographer, while the other is used to calibrate the unknown detector. Our result opens a new page in a quantum detector characterization, that allows reconstruction of an inherently quantum measure of an arbitrary detector's performance -POVM - while explicitly providing an advantage over classical methods in accuracy, thus advancing quantum technologies.

Citation

Physical Review Letters

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevLett.108.253601

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Keywords

quantum information

Citation

Migdall, A. , Brida, G. , Ciavarella, L. , Degiovanni, I. , Genovese, M. , , M. , A., M. , Piacentini, F. and Polyakov, S. (2012), Ancilla assisted calibration of a measuring apparatus, Physical Review Letters, [online], https://doi.org/10.1103/PhysRevLett.108.253601, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=910445 (Accessed October 11, 2025)