On entanglement evolution across defects in critical chains
1 Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna Boltzmanngasse 5, A-1090 Wien, Austria
2 Fachbereich Physik, Freie Universität Berlin - Arnimallee 14, D-14195 Berlin, Germany
Received: 4 June 2012
Accepted: 26 June 2012
We consider a local quench where two free-fermion half-chains are coupled via a defect. We show that the logarithmic increase of the entanglement entropy is governed by the same effective central charge which appears in the ground-state properties and which is known exactly. For unequal initial filling of the half-chains, we determine the linear increase of the entanglement entropy.
PACS: 03.65.Ud – Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.) / 03.67.Mn – Entanglement measures, witnesses, and other characterizations / 05.30.Fk – Fermion systems and electron gas
© EPLA, 2012