Jens H. Bardarson, Frank Pollmann, Joel E. Moore
An important and incompletely answered question is whether a closed quantum
system of many interacting particles can be localized by disorder. The time
evolution of an initially unentangled state is studied for a random-field XXZ
Hamiltonian. Interactions induce a dramatic change in the propagation of
entanglement and a smaller change in the propagation of particles. For even
weak interactions, when the system is thought to be in a many-body localized
phase, entanglement shows neither localized nor diffusive behavior but grows
without limit in an infinite system: interactions act as a singular
perturbation on the localized state with no interactions. The significance for
proposed atomic experiments is that local measurements will show a large but
non-thermal entropy in the many-body localized state, which develops over a
diverging time scale as in glassy systems.
View original:
http://arxiv.org/abs/1202.5532
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