A quantum measurement can be described by a set of matrices, one for each possible outcome, which represents the positive operator-valued measure (POVM) of the sensor. Efficient protocols of POVM extraction for arbitrary sensors are required. We present the first experimental POVM reconstruction that takes explicit advantage of a quantum resource, i.e., nonclassical correlations with an ancillary state. A POVM of a photon-number-resolving detector is reconstructed by using strong quantum correlations of twin beams generated by parametric down-conversion. Our reconstruction method is more statistically robust than POVM reconstruction methods that use classical input states.
Ancilla-assisted calibration of a measuring apparatus / Brida, Giorgio; L., Ciavarella; Degiovanni, IVO PIETRO; Genovese, Marco; A., Migdall; M. G., Mingolla; M. G. A., Paris; Piacentini, Fabrizio; S. V., Polyakov. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 108:(2012), p. 253601.253601. [10.1103/PhysRevLett.108.253601]
Ancilla-assisted calibration of a measuring apparatus
BRIDA, GIORGIO;DEGIOVANNI, IVO PIETRO;GENOVESE, MARCO;PIACENTINI, FABRIZIO;
2012
Abstract
A quantum measurement can be described by a set of matrices, one for each possible outcome, which represents the positive operator-valued measure (POVM) of the sensor. Efficient protocols of POVM extraction for arbitrary sensors are required. We present the first experimental POVM reconstruction that takes explicit advantage of a quantum resource, i.e., nonclassical correlations with an ancillary state. A POVM of a photon-number-resolving detector is reconstructed by using strong quantum correlations of twin beams generated by parametric down-conversion. Our reconstruction method is more statistically robust than POVM reconstruction methods that use classical input states.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
