Two methods for measuring Bell nonlocality via local unitary invariants of two-qubit systems in Hong-Ou-Mandel interferometers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F18%3A73587590" target="_blank" >RIV/61989592:15310/18:73587590 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/pra/pdf/10.1103/PhysRevA.97.012107" target="_blank" >https://journals.aps.org/pra/pdf/10.1103/PhysRevA.97.012107</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.97.012107" target="_blank" >10.1103/PhysRevA.97.012107</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Two methods for measuring Bell nonlocality via local unitary invariants of two-qubit systems in Hong-Ou-Mandel interferometers

Popis výsledku v původním jazyce

We describe a direct method to experimentally determine local two-qubit invariants by performing interferometric measurements on multiple copies of a given two-qubit state. We use this framework to analyze two different kinds of two-qubit invariants of Makhlin and Jing et al. These invariants allow us to fully reconstruct any two-qubit state up to local unitaries. We demonstrate that measuring three invariants is sufficient to find, e.g., the optimal Bell inequality violation. These invariants can be measured with local or nonlocal measurements. We show that the nonlocal strategy that follows from Makhlin&apos;s invariants is more resource efficient than local strategy following from the invariants of Jing et al. To measure all of the Makhlin&apos;s invariants directly one needs to use both two-qubit singlets and three-qubit W-state projections on multiple copies of the two-qubit state. This problem is equivalent to a coordinate system handedness measurement. We demonstrate that these three-qubit measurements can be performed by utilizing Hong-Ou-Mandel interference, which gives significant speedup in comparison to the classical handedness measurement. Finally, we point to potential applications of our results in quantum secret sharing.

Název v anglickém jazyce

Two methods for measuring Bell nonlocality via local unitary invariants of two-qubit systems in Hong-Ou-Mandel interferometers

Popis výsledku anglicky

We describe a direct method to experimentally determine local two-qubit invariants by performing interferometric measurements on multiple copies of a given two-qubit state. We use this framework to analyze two different kinds of two-qubit invariants of Makhlin and Jing et al. These invariants allow us to fully reconstruct any two-qubit state up to local unitaries. We demonstrate that measuring three invariants is sufficient to find, e.g., the optimal Bell inequality violation. These invariants can be measured with local or nonlocal measurements. We show that the nonlocal strategy that follows from Makhlin&apos;s invariants is more resource efficient than local strategy following from the invariants of Jing et al. To measure all of the Makhlin&apos;s invariants directly one needs to use both two-qubit singlets and three-qubit W-state projections on multiple copies of the two-qubit state. This problem is equivalent to a coordinate system handedness measurement. We demonstrate that these three-qubit measurements can be performed by utilizing Hong-Ou-Mandel interference, which gives significant speedup in comparison to the classical handedness measurement. Finally, we point to potential applications of our results in quantum secret sharing.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10306 - Optics (including laser optics and quantum optics)

Projekt

<a href="/cs/project/GA17-10003S" target="_blank" >GA17-10003S: Pokročilá lineárně-optická hradla pro kvantové komunikační sítě</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Physical Review A

ISSN

2469-9926

e-ISSN

—

Svazek periodika

97

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

"012107-1"-"012107-9"

Kód UT WoS článku

000419760300001

EID výsledku v databázi Scopus

2-s2.0-85042041676