Variational Monte Carlo study of spin-dependent correlations in liquidHe3

Abstract
The Jastrow trial function for the ground state of liquid He3 is generalized by the introduction of two-body correlations which depend on the z components of the nuclear spins. For this trial function both Metropolis Monte Carlo and standard Fermi-hypernetted-chain evaluations of the energy and the like-spin and unlike-spin radial distribution functions are carried out. It is demonstrated that as a consequence of the omission of elementary diagrams the latter procedure suffers large errors in the physically relevant domain of variational parameters, where the dynamical correlation hole associated with unlike-spin pairs is larger than that for like-spin pairs. In the complementary regime where the like-spin dynamical correlations are the more important, the errors of the Fermihypernetted-chain procedure are less serious. In agreement with previous studies, it is found that spin-dependent correlations can make an appreciable contribution (~0.2 K or more) to the ground-state binding energy of liquid He3.