Witnessing negativity of Wigner function by estimating fidelities of catlike states from homodyne measurements

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F13%3A33144347" target="_blank" >RIV/61989592:15310/13:33144347 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1103/PhysRevA.87.062115" target="_blank" >http://dx.doi.org/10.1103/PhysRevA.87.062115</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.87.062115" target="_blank" >10.1103/PhysRevA.87.062115</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Witnessing negativity of Wigner function by estimating fidelities of catlike states from homodyne measurements

Popis výsledku v původním jazyce

We derive sampling functions for estimation of quantum-state fidelity with Schrodinger-cat-like states, which are defined as superpositions of two coherent states with opposite amplitudes. We also provide sampling functions for fidelity with squeezed Fock states that can approximate the catlike states and can be generated from Gaussian squeezed states by conditional photon subtraction. The fidelities can be determined by averaging the sampling functions over quadrature statistics measured by homodyne detection. The sampling functions are designed such that they can compensate for losses and inefficient homodyning provided that the overall efficiency exceeds a certain threshold. The fidelity with an odd coherent state and the fidelity with a squeezed odd Fock state provide convenient witnesses of negativity of the Wigner function of the measured state. The negativity of the Wigner function at the origin of phase space is certified if any of these fidelities exceeds 0.5. Finally, we disc

Název v anglickém jazyce

Witnessing negativity of Wigner function by estimating fidelities of catlike states from homodyne measurements

Popis výsledku anglicky

We derive sampling functions for estimation of quantum-state fidelity with Schrodinger-cat-like states, which are defined as superpositions of two coherent states with opposite amplitudes. We also provide sampling functions for fidelity with squeezed Fock states that can approximate the catlike states and can be generated from Gaussian squeezed states by conditional photon subtraction. The fidelities can be determined by averaging the sampling functions over quadrature statistics measured by homodyne detection. The sampling functions are designed such that they can compensate for losses and inefficient homodyning provided that the overall efficiency exceeds a certain threshold. The fidelity with an odd coherent state and the fidelity with a squeezed odd Fock state provide convenient witnesses of negativity of the Wigner function of the measured state. The negativity of the Wigner function at the origin of phase space is certified if any of these fidelities exceeds 0.5. Finally, we disc

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BH - Optika, masery a lasery

OECD FORD obor

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Projekt

<a href="/cs/project/GAP205%2F12%2F0577" target="_blank" >GAP205/12/0577: Spolehlivé vysoce nelineární optické kvantové zpracování informace</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2013

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review A

ISSN

1050-2947

e-ISSN

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Svazek periodika

87

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

"062115-1"-"062115-9"

Kód UT WoS článku

000320764300005

EID výsledku v databázi Scopus

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