Excitation spectrum of superfluid 4He

Abstract

An empirical form for the interaction between atoms of superfluid ⁴He is proposed for the prediction of the structure of excitation spectrum of the liquid on the basis of Bogoliubov theory for weakly interacting bosons. An over-all satisfactory agreement is achieved between theory and experiment. The results, obtained for sound velocity, critical velocity, energy gap, effective mass of roton, wave-vector at the energy minimum, momentum variation of phase and group velocities, support the philosophy of the assumption of the existence of real interatomic potential in the momentum space near 1.1 K.