Entanglement in fermion systems

We analyze the problem of quantifying entanglement in pure and mixed states of fermionic systems with fixed number parity yet not necessarily fixed particle number. The mode entanglement between one single-particle level and its orthogonal complement is first considered, and an entanglement entropy...

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Detalles Bibliográficos
Autores principales: Gigena, Nicolás Alejandro, Rossignoli, Raúl
Formato: Articulo
Lenguaje:Español
Publicado: 2015
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/75315
Aporte de:
id I19-R120-10915-75315
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Español
topic Ciencias Exactas
Fermion systems
quantum entanglement
spellingShingle Ciencias Exactas
Fermion systems
quantum entanglement
Gigena, Nicolás Alejandro
Rossignoli, Raúl
Entanglement in fermion systems
topic_facet Ciencias Exactas
Fermion systems
quantum entanglement
description We analyze the problem of quantifying entanglement in pure and mixed states of fermionic systems with fixed number parity yet not necessarily fixed particle number. The mode entanglement between one single-particle level and its orthogonal complement is first considered, and an entanglement entropy for such a partition of a particular basis of the single-particle Hilbert spaceHis defined. The sum over all single-particle modes of this entropy is introduced as a measure of the total entanglement of the system with respect to the chosen basis and it is shown that its minimum over all bases ofHis a function of the one-body density matrix. Furthermore, we show that if minimization is extended to all bases related through a Bogoliubov transformation, then the entanglement entropy is a function of the generalized one-body density matrix. These results are then used to quantify entanglement in fermion systems with four single-particle levels. For general pure states of such a system a closed expression for the fermionic concurrence is derived, which generalizes the Slater correlation measure defined in [J. Schliemann et al, Phys. Rev. A 64, 022303 (2001)], implying that particle entanglement may be seen as minimum mode entanglement . It is also shown that the entanglement entropy defined before is related to this concurrence by an expression analogous to that of the two-qubit case. For mixed states of this system the convex roof extension of the previous concurrence and entanglement entropy are evaluated analytically, extending the results of previous ref. to general states.
format Articulo
Articulo
author Gigena, Nicolás Alejandro
Rossignoli, Raúl
author_facet Gigena, Nicolás Alejandro
Rossignoli, Raúl
author_sort Gigena, Nicolás Alejandro
title Entanglement in fermion systems
title_short Entanglement in fermion systems
title_full Entanglement in fermion systems
title_fullStr Entanglement in fermion systems
title_full_unstemmed Entanglement in fermion systems
title_sort entanglement in fermion systems
publishDate 2015
url http://sedici.unlp.edu.ar/handle/10915/75315
work_keys_str_mv AT gigenanicolasalejandro entanglementinfermionsystems
AT rossignoliraul entanglementinfermionsystems
bdutipo_str Repositorios
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