Quantum quenches in disordered systems: Approach to thermal equilibrium   without a typical relaxation time
  We study spectral properties and the dynamics after a quench of one-dimensional spinless fermions with short-range interactions and long-range random hopping. We show that a sufficiently fast decay of the hopping term promotes localization effects at finite temperature, which prevents thermalization even if the classical motion is chaotic. For slower decays, we find that thermalization does occur. However, within this model, the latter regime falls in an unexpected universality class, namely, observables exhibit a power-law (as opposed to an exponential) approach to their thermal expectation values. 
Ehsan Khatami, Marcos Rigol, Armando Rela\~no, and Antonio M.   Garcia-Garcia
cond-mat.dis-nn cond-mat.quant-gas cond-mat.stat-mech quant-ph