Properties of He-4 in one dimension

It has been suggested recently that He-4 can be prepared and studied as a q uasi-one-dimensional quantum fluid. In this paper we calculate the static a nd dynamic properties of one-dimensional 4He using variational methods base d upon the Jastrow-Feenberg wave function and its extension to dynamic syst ems with time-dependent, correlated wave functions. We calculate the zero t emperature equation of state and show that in one dimension 4He is just bar ely self-bound with a binding energy of 0.002 K at a density of 0.036 Angst rom(-1). We calculate the Feynman excitation spectrum and corrections that contain multiphonon processes and study the density dependence of the roton feature as well as the static response function. In addition we demonstrat e the presence of strong anomalous dispersion in the phonon regime. Finally , we introduce a He-3 impurity and calculate the zero concentration chemica l potential as a function of 4He linear density. We also compute the He-3- He-3 effective interaction in the He-4 background and compute the energy of dimerization. [S0163-1829(99)01241-2].