On The Ground State Of Liquid Helium Four PDF Download

A trial wave function describing the ground state of a quantum system of N interacting bosons is written in the Jastrow form, a product of pair functions. With the interaction potential chosen to represent liquid helium four, and with the parameterized form of the pair function chosen to include a long range term which has been found necessary to represent the zero point motion of the long wavelength density oscillations, a variational calculation has been performed using an accurate approximate integral equation for the pair distribution function. The essential results are that including the zero point motion in the wave function tends to lower the energy, raise the equilibrium density, corrects the behavior of the structure function and the momentum distribution of the particles in the low wave number region, and slightly decreases the Bose-Einstein condensate fraction. The value of the lower limit on the wavelength of the density oscillations was determined variationally to be about three interparticle spacings. (Author).