Subject: [Ayudantes2] Coloquio extraodinario. Departamento de Física

From: "Gabi Pasquini" <[email-masked]>
Date: Mon, 1 Sep 2008 11:46:21 -0300

COLOQUIO EXTRAORDINARIO  
  
          COLOQUIOS DEL DEPARTAMENTO DE FÍSICA
                                            FCEyN - UBA

                                    Charla, café y galletitas
                        En el Aula Federman, 1er piso Pabellón I.
                                  Ciudad Universitaria 

                       El próximo  viernes 5 de septiembre a las 14 hs 
     
            A two-particle Aharonov-Bohm effect: 

Bell Inequality and Quantum Tomography  at finite temperature 

                         Markus Buttiker

                              University of Geneva

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RESUMEN:
 
In small conductors at low temperatures, the wave nature of electrons becomes important. I briefly review the development of the  Aharonov-Bohm  (AB) effect as a tool to demonstrate quantum interference and discuss a novel AB effect in which two particles are necessary to enclose a flux, which can be tested by current fluctuations known as shot noise. Of interest are geometries  where the two-particle AB effect even when there exists no single-particle AB effect. At zero-temperature the novel AB effect is a witness of orbital entanglement: its amplitude directly determines the degree of violation of a Bell inequality. At finite temperatures the entanglement detectable by currents and current correlations is quantified by the reduced density matrix. In contrast to optical detectors, electrical conductors can  exchange particles with the sample, necessitating a completely novel discussion of entanglement detection .