In a recent paper, Roux [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.79. 021608 79, 021608(R) (2009)] argued that thermalization in a Bose-Hubbard system, after a quantum quench, follows from the approximate Boltzmann distribution of the overlap between the initial state and the eigenstates of the final Hamiltonian. We show here that the distribution of the overlaps is in general not related to the canonical (or microcanonical) distribution and, hence, it cannot explain why thermalization occurs in quantum systems.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics