Event DetailsEvent Dates: Monday, August 25, 2014 - 3:00pmSeminar Location: JILA X317Speaker Name(s): Dr. Michael Kastner Speaker Affiliation(s): National Institute for Theoretical Physics, South Africa Seminar Type/SubjectScientific Seminar Type: JILA Public SeminarEvent Details & Abstract: A striking feature of the nonequilibrium dynamics of long-range interacting lattice systems is explored, namely the absence of a finite group velocity for the spreading of correlations or information. We study classical and quantum lattice models with long-ranged interactions decaying asymptotically for large distances like a power law. For exponents larger than the lattice dimensionality, a Lieb-Robinson-type bound effectively restricts the spreading of correlations to a causal region, but allows supersonic propagation. For any exponents smaller than the lattice dimension, we construct Hamiltonians giving rise to quantum channels with capacities not restricted to a causal region. Numerical and analytical results reveal the presence of an approximate sound cone for large exponents, and supersonic propagation for small ones. The results should be relevant for the understanding of equilibration and thermalisation in long-range interacting quantum systems. Finally, experimental implementations are briefly discussed.