Quenching Dynamics and Quantum Information
Abstract
We review recent studies on the measures of zero temperature quantum correlations namely, the quantum entanglement (concurrence) and discord present in the final state of a transverse XY spin chain following a quench through quantum critical points; the aim of these studies is to explore the scaling of the above quantities as a function of the quench rate. A comparative study between the concurrence and the quantum discord shows that their behavior is qualitatively the same though there are quantitative differences. For the present model, the scaling of both the quantities are given by the scaling of the density of the defect present in the final state though one cannot find a closed form expression for the discord. We also extend our study of quantum discord to a transverse Ising chain in the presence of a three spin interaction. Finally, we present a study of the dynamical evolution of quantum discord and concurrence when two central qubits, initially prepared in a Werner state, are coupled to the environmental XY spin chain which is driven through quantum critical points. The qualitative behavior of quantum discord and concurrence are found to be similar as that of the decoherence factor.
 Publication:

International Journal of Modern Physics B
 Pub Date:
 January 2013
 DOI:
 10.1142/S0217979213450367
 arXiv:
 arXiv:1206.0559
 Bibcode:
 2013IJMPB..2745036N
 Keywords:

 Quantum phase transitions;
 nonequilibrium dynamics;
 concurrence;
 discord;
 Quantum Physics;
 Condensed Matter  Statistical Mechanics
 EPrint:
 21 pages, 12 figures, Submitted to Int. J. Mod. Phys. B, special issue "Classical Vs Quantum correlations in composite systems" edited by L. Amico, S. Bose, V. Korepin and V. Vedral. arXiv admin note: text overlap with arXiv:1105.4442