BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Entanglement and fidelity in topological superconductors - Prof. P
 edro Sacramento\, University of Lisbon
DTSTART:20130912T131500Z
DTEND:20130912T141500Z
UID:TALK47197@talks.cam.ac.uk
CONTACT:Antonio garcia
DESCRIPTION:A p-wave superconductor\, with Rashba spin-orbit coupling and 
 a Zeeman term displays various topological phases that can be detected in 
 various ways such as the Chern number or by gapless edge states. In this t
 alk we use bulk and local quantum information methods to detect the transi
 tions. We show that the von Neumann entropy\, the entanglement spectrum\, 
 fidelity and the fidelity spectrum may be used to signal the transitions. 
 The nature of the phases and their changes are clarified by the eigenvecto
 rs of the k-space reduced density matrix and by the eigenvectors of the k-
 fidelity operator. A signature of the various phase transitions between tw
 o points in the parameter space is encoded in the k-space fidelity operato
 r. We also show that local entanglement entropy and the topological entang
 lement entropy also signal the topological transitions. We find that a der
 ivative of the entanglement entropy shows approximate plateaus that are re
 lated to the Chern numbers. We also suggest that the topological entanglem
 ent entropy in a half-cylinder geometry is closely related to the number o
 f edge states.
LOCATION:TCM Seminar room\, 530 Mott
END:VEVENT
END:VCALENDAR