13. Solid and Liquid Helium

摘要: Publisher Summary This chapter discusses that the condensed phases of stable isotopes helium, 3 He, and 4 He continue to be high interest scientists in general neutron scatterers particular. stems from fact these substances form prototype examples nature quantum solids liquids interacting bosons fermions. A very meaningful comparison results first-principles theoretical calculations, with experiment, is possible for materials, because interatomic potential reasonably simple well known. Different regions this can readily probed experiments by varying pressure temperature vary distance, an extremely important advantage. The highlights some most features structure excitations He; concentrating on scattering measurements, those developments have direct consequences studies.