title: Semiclassical analysis of the Bogoliubov spectrum in the Bose-Hubbard model.
abstract: We analyze the Bogoliubov spectrum of the Bose-Hubbard model with a finite number of sites and Bose particles by using a semiclassical approach. This approach allows us to take into account the finite-size effects responsible for evolution of the Bogoliubov spectrum into an irregular (chaotic) spectrum at higher energies. A manifestation of this transition for the excitation dynamics of the Bose-Hubbard system is discussed as well.
authors.affiliation: Kirensky Institute of Physics, 660036 Krasnoyarsk, Russia.
authors.forename: Andrey R
authors.initials: AR
authors.lastname: Kolovsky