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Date: | 2016 |
Abstract: | Entanglement is a ubiquitous feature of low temperature systems and believed to be highly relevant for the dynamics of condensed matter properties and quantum computation even at higher temperatures. The experimental certification of this paradigmatic quantum effect in macroscopic high temperature systems is constrained by the limited access to the quantum state of the system. In this paper we show how macroscopic observables beyond the mean energy of the system can be exploited as proxy witnesses for entanglement detection. Using linear and semi-definite relaxations we show that all previous approaches to this problem can be outperformed by our proxies, i. e. entanglement can be certified at higher temperatures without access to any local observable. For an efficient computation of proxy witnesses one can resort to a generalised grand canonical ensemble, enabling entanglement certification even in complex systems with macroscopic particle numbers. |
Grants: | Ministerio de Economía y Competitividad FIS2008-01236 Ministerio de Economía y Competitividad FIS2013-40627-P Ministerio de Ciencia e Innovación JCI2012-14155 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-966 |
Note: | Altres ajuts: European Research Council (Advanced Grant 'IRQUAT'). European Commission (STREP 'RAQUEL') |
Rights: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. |
Language: | Anglès |
Document: | Article ; recerca ; Versió publicada |
Subject: | Entanglement ; Entropy ; Thermodynamics |
Published in: | New journal of physics, Vol. 18 (January 2016) , art. 15002, ISSN 1367-2630 |
17 p, 1.6 MB |