Symmetry restoration and quantumness reestablishment
Data(s) |
27/10/2015
27/10/2015
18/09/2014
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Resumo |
A realistic quantum many-body system, characterized by a generic microscopic Hamiltonian, is accessible only through approximation methods. The mean field theories, as the simplest practices of approximation methods, commonly serve as a powerful tool, but unfortunately often violate the symmetry of the Hamiltonian. The conventional BCS theory, as an excellent mean field approach, violates the particle number conservation and completely erases quantumness characterized by concurrence and quantum discord between different modes. We restore the symmetry by using the projected BCS theory and the exact numerical solution and find that the lost quantumness is synchronously reestablished. We show that while entanglement remains unchanged with the particle numbers, quantum discord behaves as an extensive quantity with respect to the system size. Surprisingly, discord is hardly dependent on the interaction strengths. The new feature of discord offers promising applications in modern quantum technologies. |
Identificador |
Scientific Reports 4 2014 : (2014) // Article ID 6377 2045-2322 http://hdl.handle.net/10810/15998 10.1038/srep06377 |
Idioma(s) |
eng |
Publicador |
Nature Publishing Group |
Relação |
http://www.nature.com/articles/srep06377#abstract |
Direitos |
This work is licensed under a Creative Commons Attribution-NonCommercial- NoDerivs 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the material. To view a copy of this license, visit http:// creativecommons.org/licenses/by-nc-nd/4.0/ www.nature.com/scientificreports SCIENTIFIC REPORTS info:eu-repo/semantics/openAccess |
Palavras-Chave | #qubits #quantum information |
Tipo |
info:eu-repo/semantics/article |