Microscopic calculation of the phonon-roton branch in superfluid ${}^4$He

Abstract

Diffusion Monte Carlo results for the phonon-roton excitation branch in bulk liquid ${}^4$He at zero temperature are presented. The sign problem associated to the excited wave function has been dealt both with the fixed-node approximation and the released-node technique. The upper bounds provided by the fixed-node approximation are shown to become exact when using the released-node method. An excellent agreement with experimental data is achieved both at the equilibrium and near the freezing densities.

12 pages, RevTex, 3 ps figures included

References in corpus (2)

• Monte Carlo Analysis of a New Interatomic Potential for He
• Vortex excitation in superfluid 4He: A Diffusion Monte Carlo study

Cited by in corpus (5)

• Quantum phase transition in a two-dimensional system of dipoles
• The dispersion relation of Landau elementary excitations and the thermodynamic properties of superfluid ${}^4$He
• Quantum Monte Carlo simulation of overpressurized liquid 4He
• A Quantum Monte Carlo Study of Static Properties of One 3He Atom in Superfluid 4He
• Quantum Monte Carlo study of small pure and mixed spin-polarized tritium clusters