We have studied the excitation spectrum of the specific two-dimensional model of strongly interacting Bose particles via mapping of the many-body Schrödinger equation in imaginary time to the classical stochastic dynamics. In a broad range of coupling strengths α, a roton-like spectrum is found, with the roton gap being extremely small in natural units. A single quantum phase transition between a strongly correlated superfluid and a quantum Berezinsky crystal is found.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 21 Mar 2011|