Comment on "Logarithmic Oscillators: Ideal Hamiltonian Thermostats"   [arXiv 1203.5968]
  Campisi, Zhan, Talkner and H\"anggi have recently proposed a novel Hamiltonian thermostat which they claim may be used both in simulations and experiments [arXiv:1203.5968v4]. We show, however, that this is not possible due to the length and time scales involved, which depend exponentially on the total energy of the system. The implementation suggested by Campisi et alii implies equilibration times greater than the age of the universe for systems with more than a few dozen particles. 
Marc Mel\'endez, William G. Hoover and Pep Espa\~nol
cond-mat.stat-mech physics.class-ph