• Feb 05 2013

    WITS Node Seminar: Prof Michael Kastner (NITheP Stellenbosch Node)

    The National Institute for Theoretical Physics, and the Centre for Theoretical Physics, School of Physics, would like to invite to its coming talk in the theory seminar series, entitled:

    "Relaxation timescales in closed long-range quantum spin models"

    to be presented by Prof. Michael Kastner (NITheP/Stellenbosch)

    Abstract: The approach to equilibrium is studied for long-range quantum Ising models where the interaction strength decays like $r^{ -alpha}$ at large distances $r$. For a class of initial conditions, exact analytic results are obtained in arbitrary lattice dimension, both for ferromagnetic and antiferromagnetic coupling, and hence also in the presence of geometric frustration. In contrast to the nearest-neighbor case, we find that correlation functions decay in time like stretched or compressed exponentials. Provided the long-range character of the interactions is sufficiently strong, pronounced prethermalization plateaus are observed and relaxation time scales are widely separated. Specializing to a triangular lattice in two spatial dimensions, we propose to utilize these results for benchmarking of a recently developed ion-trap based quantum simulator.

    Date: Tuesday, 5th February 2013
    Venue: Frank Nabarro Lecture Theatre P216
    Time: 13.20 - 14.10

    For more information please contact:

    Alan S. Cornell

    School of Physics
    University of the Witwatersrand
    Private Bag 3
    Wits 2050
    South Africa