Neutron Scattering Study of Elementary Excitations in Liquid Helium-3

Abstract

The neutron inelastic scattering function of liquid helium-3 at 0.015 K has been measured for wave vectors in the range $0.8{\AA{}}^{\ensuremath{-}1}<~q<~2.2{\AA{}}^{\ensuremath{-}1}$. For $q<1.4$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$, the scattering function contains two peaks. The peak at lower energy is due to spin-fluctuation scattering in the particle-hole region while the peak at higher energy is identified to be the zero sound mode. By comparing the measured structure factor with the x-ray structure factor, the spin-dependent scattering cross section and the corresponding structure factor are determined.