[Todos] Recordatorio Seminario del IFLP

[Maria Virginia Manias]

*COLOQUIOS y SEMINARIOS del IFLP*

*MARTES 4 de DICIEMBRE – 11hs*


*TÍTULO**:* *Attainability of the quantum information bound in pure state
models *

*EXPOSITOR:* * Dr. Fabricio Toscano*
Prof. Associado do Instituto de Física da Universidade Federal do Rio de
Janeiro (UFRJ) - Brasil

*RESUMEN**: *The attainability of the quantum Cramér-Rao bound [QCR], the
ultimate limit in the precision of the estimation of a physical parameter,
requires the saturation of the quantum information bound [QIB]. This occurs
when the Fisher information associated to a given measurement on the
quantum state of a system which encodes the information about the parameter
coincides with the quantum Fisher information associated to that quantum
state.
Braunstein and Caves [PRL 72, 3439 (1994)] have shown that the QIB can
always be achieved via a projective measurement in the eigenvectors basis
of an observable called symmetric logarithmic derivative. However, such
projective measurement depends, in general, on the value of the parameter
to be estimated. Requiring, therefore, the previous knowledge of the
quantity one is trying to estimate. For this reason, it is important to
investigate under which situation it is possible to saturate the QCR
without previous information about the parameter to be estimated.
Here, we show the complete solution to the problem of which are all the
initial pure states and  the projective measurements that allow the global
saturation of the QIB, without the knowledge of the true value of the
parameter, when the information about the parameter is encoded in the
system by a unitary process.



<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
Libre
de virus. www.avg.com
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
<#m_3759536966608586645_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
------------ próxima parte ------------
Se ha borrado un adjunto en formato HTML...
URL: <http://mail.fisica.unlp.edu.ar/pipermail/todos/attachments/20181203/09e543c5/attachment.html>