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TT: Fachverband Tiefe Temperaturen
TT 52: CE: Low-dimensional Systems - Models 1
TT 52.8: Talk
Thursday, March 17, 2011, 16:00–16:15, HSZ 105
Energy dynamics out of equilibrium in low dimensional quantum magnets — •Stephan Langer1, Markus Heyl1, Ian McCulloch2, and Fabian Heidrich-Meisner1 — 1Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, LMU München, Germany — 2School of physical Sciences, The University of Queensland, Brisbane, Australia
We
investigate the real-time dynamics of the energy density in
spin-1/2 chains and ladders, starting from initial states with an
inhomogeneous profile of bond energies, extending our
previous work on the dynamics of spin-density wave packets [1].
These simulations are carried out using the adaptive
time-dependent density matrix renormalization group algorithm. We
analyze the time-dependence of the spatial variance of the bond
energies which yields necessary criteria for ballistic or
diffusive energy dynamics. In the case of the XXZ chain, our
results are consistent with ballistic behavior, both in the
massless and the massive phase. For the massless regime, we
compare our numerical results to predictions from bosonization
for, e.g., the velocity that the initial perturbation spreads
with. In the case of ladders, we find an involved dynamics whose
qualitative interpretation is still under scrutiny.
Langer et al. Phys. Rev. B 79, 214409 (2009)