Structure of the excitation spectrum of liquid [sup 4]He

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.16550· OSTI ID:6937476

Blagoveshchenskii, N M ^[1]; Bogoyavlenskii, I V; Karnatsevich, L V ^[2]; Kozlov, Z A ^[3]; Kolobrodov, V G ^[2]; Priezzhev, V B ^[3]; Puchkov, A V; Skomorokhov, A N ^[1]; Yarunin, V S ^[3]

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1. Institute of Physics and Power Engineering, Obninsk (Russian Federation)
2. Institute of Physics and Technology, Khar'kov (Ukraine)
3. Joint Institute for Nuclear Research, 141980, Dubna (Russian Federation)

Results of high-resolution measurements of the inelastic scattering of neutrons from normal and superfluid [sup 4]He are presented. A complicated structure of peaks corresponding to phonon-maxon-roton excitations is observed. At [ital T][lt][ital T][sub [lambda]], the scattering can be described by a narrow peak plus a wide component. The relative intensity of the narrow and wide components in the maxon-roton region follows the temperature dependence of density of the Bose condensate. Above [ital T][sub [lambda]], for the wave vectors [ital q][gt]0.65 A[sup [minus]1], only the wide component exists. In the long-wave region ([ital q][lt]0.65 A[sup [minus]1]), a considerable transformation of peaks with changing temperature occurs as well, although the two-component structure persists in the normal phase.

• OSTI ID: 6937476
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:22; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665420* -- Superfluidity-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOSE-EINSTEIN CONDENSATION
COHERENT SCATTERING
DIFFRACTION
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EXCITATION
FLUIDS
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LANDAU LIQUID HELIUM THEORY
LIGHT NUCLEI
NEUTRON DIFFRACTION
NUCLEI
QUANTUM FLUIDS
QUASI PARTICLES
SCATTERING
STABLE ISOTOPES