Quantum thermalization: anomalous slow relaxation due to percolation-like dynamics Academic Article uri icon

abstract

  • We employ a minimal model of a bi-partite $N$-boson system, where $\hbar=1/N$ plays the role of the Planck constant, to study the thermalization of the constituent subsystems. We find that the rate of relaxation towards equilibrium violates the standard linear-response (Kubo) formulation, even when the underlying dynamics is highly chaotic. This anomaly originates from an $\hbar$-dependent sparsity of the underlying quantum network of transitions. Consequently the relaxation rate acquires an anomalous $\hbar$ dependence that reflects percolation-like dynamics in energy space. This {\em dynamical} anomaly is distinct from lack of quantum ergodicity due to classical or quantum localization.

publication date

  • January 1, 2015