Efficient qubit phase estimation using adaptive measurements


Por: Rodriguez-Garcia, Marco A., Perez Castillo, Isaac, Barberis-Blostein, P.

Publicada: 4 jun 2021
Resumen:
Estimating correctly the quantum phase of a physical system is a central problem in quantum parameter estimation theory due to its wide range of applications from quantum metrology to cryptography. Ideally, the optimal quantum estimator is given by the so-called quantum Cramer-Rao bound, so any measurement strategy aims to obtain estimations as close as possible to it. However, more often than not, the current state-of-the-art methods to estimate quantum phases fail to reach this bound as they rely on maximum likelihood estimators of non-identifiable likelihood functions. In this work we thoroughly review various schemes for estimating the phase of a qubit, identifying the underlying problem which prohibits these methods to reach the quantum Cramer-Rao bound, and propose a new adaptive scheme based on covariant measurements to circumvent this problem. Our findings are carefully checked by Monte Carlo simulations, showing that the method we propose is both mathematically and experimentally more realistic and more efficient than the methods currently available.

Filiaciones:
Rodriguez-Garcia, Marco A.:
 Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Sistemas, Ciudad De Mexico 04510, Mexico

Perez Castillo, Isaac:
 Univ Autonoma Metropolitana Iztapalapa, Dept Fis, San Rafael Atlixco 186, Ciudad De Mexico 09340, Mexico

Barberis-Blostein, P.:
 Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Sistemas, Ciudad De Mexico 04510, Mexico
ISSN: 2521327X
Editorial
VEREIN FORDERUNG OPEN ACCESS PUBLIZIERENS QUANTENWISSENSCHAF, BOLTZMANNGASSE 3, WIEN, 1090, AUSTRIA, Austria
Tipo de documento: Article
Volumen: 5 Número:
Páginas:
WOS Id: 000659218100001
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