Error estimation of different schemes to measure spin-squeezing inequalities

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Bönsel, Jan Lennart, Imai, Satoya, Liu, Ye-Chao, Gühne, Otfried
Format: Preprint
Publié: 2023
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866909293213646848
author Bönsel, Jan Lennart
Imai, Satoya
Liu, Ye-Chao
Gühne, Otfried
author_facet Bönsel, Jan Lennart
Imai, Satoya
Liu, Ye-Chao
Gühne, Otfried
contents How can we analyze quantum correlations in large and noisy systems without quantum state tomography? An established method is to measure total angular momenta and employ the so-called spin-squeezing inequalities based on their expectations and variances. This allows detection of metrologically useful entanglement, but efficient strategies for estimating such nonlinear quantities have yet to be determined. In this paper we show that spin-squeezing inequalities can not only be evaluated by measurements of the total angular momentum but also by two-qubit correlations, either involving all pair correlations or randomly chosen pair correlations. Then we analyze the estimation errors of our approaches in terms of a hypothesis test. For this purpose, we discuss how error bounds can be derived for nonlinear estimators with the help of their variances, characterizing the probability of falsely detecting a separable state as entangled. We focus on the spin-squeezing inequalities in multiqubit systems. Our methods, however, can also be applied to spin-squeezing inequalities for qudits or for the statistical treatment of other nonlinear parameters of quantum states.
format Preprint
id arxiv_https___arxiv_org_abs_2311_17845
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Error estimation of different schemes to measure spin-squeezing inequalities
Bönsel, Jan Lennart
Imai, Satoya
Liu, Ye-Chao
Gühne, Otfried
Quantum Physics
How can we analyze quantum correlations in large and noisy systems without quantum state tomography? An established method is to measure total angular momenta and employ the so-called spin-squeezing inequalities based on their expectations and variances. This allows detection of metrologically useful entanglement, but efficient strategies for estimating such nonlinear quantities have yet to be determined. In this paper we show that spin-squeezing inequalities can not only be evaluated by measurements of the total angular momentum but also by two-qubit correlations, either involving all pair correlations or randomly chosen pair correlations. Then we analyze the estimation errors of our approaches in terms of a hypothesis test. For this purpose, we discuss how error bounds can be derived for nonlinear estimators with the help of their variances, characterizing the probability of falsely detecting a separable state as entangled. We focus on the spin-squeezing inequalities in multiqubit systems. Our methods, however, can also be applied to spin-squeezing inequalities for qudits or for the statistical treatment of other nonlinear parameters of quantum states.
title Error estimation of different schemes to measure spin-squeezing inequalities
topic Quantum Physics
url https://arxiv.org/abs/2311.17845