2012/02/29 by Jens H. Bardarson, Frank Pollmann, Joel E. Moore · 2 citations
Physics and Astronomy · #cond-mat.str-el #cond-mat.dis-nn
paper · pdf · doi:10.1103/physrevlett.109.017202
published as Phys. Rev. Lett. 109, 017202 (2012) · 4 pages, 2 figures, v2. added more data
arxiv created 2012/07/10 · arxiv updated 2012/07/11
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 simple (unentangled) initial states is studied numerically for a system of interacting spinless fermions in one dimension described by the 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 nonthermal entropy in the many-body localized state. This entropy develops slowly (approximately logarithmically) over a diverging time scale as in glassy systems.