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DY 31.4: Vortrag
Mittwoch, 18. März 2020, 10:15–10:30, HÜL 186
Ergodization times and dynamical glass in classical Josephson junction chains — •Carlo Danieli1, Mithun Thudiyangal2, Yagmur Kati3, and Sergej Flach4 — 1Max Planck Institute for the Physics of Complex Physics, Noethnitzer Str. 38, 01187 Dresden, Germany — 2Department of Mathematics and Statistics, University of Massachusetts, Amherst MA 01003-4515, USA — 3Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon, Korea — 4Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon, Korea
Models of classical Josephson junction chains turn integrable in the limit of large energy densities or small Joseph- son coupling strength. Close to these limits, the Josephson coupling between superconducting grains induces a short range network. We compute distributions of finite-time averages of grain charges and extract the ergodization time TE which controls their convergence to ergodic delta distributions. We relate TE to the statistics of the fluctuations in time of the grain charges, which are dominated by fat tails. The ergodization time TE grows anomalously fast upon approaching the integrable limit as compared to the Lyapunov time TΛ - the inverse largest Lyapunov expo- nent. The microscopic reason for the observed behavior - which we labeled dynamical glass - is rooted in a growing number of grains evolving over long time in a regular fashion due to low probability of resonant interactions with the neighboring ones. We conjecture that the observed dynamical glass is Josephson junction networks irrespective of their dimensionality. Ref: Phys.Rev.Lett. 122 054102 (2019).