One description provides only probabilities for obtaining various eigenvalues of a quantum variable. The eigenvalues and the corresponding probabilities specify the expectation value of a physical observable, which is known to be a statistical property of an ensemble of quantum systems. In contrast to this paradigm, here we demonstrate a method for measuring the expectation value of a physical variable on a single particle, namely, the polarization of a single protected photon. This realization of quantum protective measurements could find applications in the foundations of quantum mechanics and quantum-enhanced measurements

Determining the quantum expectation value by measuring a single photon / Piacentini, Fabrizio; Avella, Alessio; Rebufello, Enrico; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Gramegna, Marco; Brida, Giorgio; Cohen, Eliahu; Vaidman, Lev; Degiovanni, Ivo P.; Genovese, Marco. - In: NATURE PHYSICS. - ISSN 1745-2473. - 13:12(2017), pp. 1191-1194. [10.1038/nphys4223]

Determining the quantum expectation value by measuring a single photon

Piacentini, Fabrizio;Avella, Alessio;Rebufello, Enrico;Gramegna, Marco;Brida, Giorgio;Degiovanni, Ivo P.;Genovese, Marco
2017

Abstract

One description provides only probabilities for obtaining various eigenvalues of a quantum variable. The eigenvalues and the corresponding probabilities specify the expectation value of a physical observable, which is known to be a statistical property of an ensemble of quantum systems. In contrast to this paradigm, here we demonstrate a method for measuring the expectation value of a physical variable on a single particle, namely, the polarization of a single protected photon. This realization of quantum protective measurements could find applications in the foundations of quantum mechanics and quantum-enhanced measurements
File in questo prodotto:
File Dimensione Formato  
Piacentini-2017-Determining-the-quantum-expectation.pdf

non disponibili

Tipologia: Versione editoriale
Licenza: Non Pubblico - Accesso privato/ristretto
Dimensione 794.55 kB
Formato Adobe PDF
794.55 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
1706.08918v1.pdf

accesso aperto

Tipologia: Documento in Pre-print
Licenza: Pubblico - Tutti i diritti riservati
Dimensione 2.64 MB
Formato Adobe PDF
2.64 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11696/56887
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 36
  • ???jsp.display-item.citation.isi??? 31
social impact