Optimal measurements in phase estimation: simple examples

Anno: 2016

Autori: Wasak T., Smerzi A., Pezzè L., Chwedenczuk J.

Affiliazione autori: Univ Warsaw, Inst Theoret Phys, Ul Pasteura 5, PL-02093 Warsaw, Poland; INO CNR, QSTAR, Largo Enrico Fermi 2, I-50125 Florence, Italy; LENS, Largo Enrico Fermi 2, I-50125 Florence, Italy.

Abstract: We identify optimal measurement strategies for phase estimation in different scenarios in which the interferometer acts on two-mode symmetric states. For pure states of a single qubit, we show that optimal measurements form a broad set parametrized with a continuous variable. When the state is mixed, this set reduces to merely two possible measurements. For two-qubit symmetric Werner state, we find the optimal measurement and show that estimation from the population imbalance is optimal only if the state is pure. We also determine the optimal measurements for a wide class of symmetric N-qubit Werner-like states. Finally, for a pure symmetric state of N qubits, we find under which conditions the estimation from the full N-body correlation and from the population imbalance is optimal.

Giornale/Rivista: QUANTUM INFORMATION PROCESSING

Volume: 15 (5)      Da Pagina: 2231  A: 2252

Maggiori informazioni: J. Ch. acknowledges the Foundation for Polish Science International TEAM Programme co-financed by the EU European Regional Development Fund and the support of the Polish NCBiR under the ERA-NET CHIST-ERA project QUASAR. T.W. acknowledges the Foundation for Polish Science International Ph.D. Projects Programme co-financed by the EU European Regional Development Fund and the National Science Center Grant No. DEC-2011/03/D/ST2/00200. L.P. acknowledges financial support by MIUR through FIRB Project No. RBFR08H058. This research was partially supported by the EU-STREP Project QIBEC.
Parole chiavi: Estimation theory; Quantum interferometry; Optimal measurements; Entanglement
DOI: 10.1007/s11128-016-1248-5

Citazioni: 12
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2025-01-12
Riferimenti tratti da Isi Web of Knowledge: (solo abbonati)
Link per visualizzare la scheda su IsiWeb: Clicca qui
Link per visualizzare la citazioni su IsiWeb: Clicca qui