Two Types of Quasiparticles Excited in a Bose Gas
V. N. Minasyan, K.J. Touryan
We present a novel approach for investigating the superfluid liquid 4He based on the proper use of the nonideal Bose gas model for dilute hard spheres. The results show that the presence of a macroscopic number of condensate atoms leads to the existence of a nonphysical branch, corresponding to density excitations, in addition to the continuous branch of the phonon-maxon-roton excitation spectrum.
Physical Review Letters•Jun 13, 2003•1 citation