Temperature dependence of S(Q,. omega. ) in liquid /sup 4/He under pressure

Journal Article · Thu Dec 01 04:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.11229· OSTI ID:6592815

Talbot, E F; Glyde, H R; Stirling, W G; Svensson, E C

The temperature dependence of the dynamic form factor, S(Q,..omega..), of liquid /sup 4/He at p = 20 bars has been determined by inelastic neutron scattering measurements. Two wave vectors, Q = 1.13 A/sup -1/ and Q = 2.03 A/sup -1/, corresponding to the maxon and roton regions of the phonon-roton dispersion curve, were studied over a wide range of energy transfer, (h/2..pi..)..omega... Based on previous data at SVP, Woods and Svensson proposed that S(Q,..omega..) could be represented as a sum of two components, one proportional to the superfluid density, rho/sub S/(T), and one proportional to the normal density rho/sub N/(T). The component proportional to rho/sub S/(T) contained the sharp one-phonon peak which vanished at T = T/sub lambda/. The aim here is, firstly, to present data on the temperature dependence of S(Q,..omega..) at 20 bars and, secondly, to explore whether or not the Woods-Svensson decomposition of S(Q,..omega..) holds at higher pressure. At 20 bars and for the Q values investigated here, we find that the sharp peak of S(Q,..omega..) does indeed decrease rapidly in intensity as T increases and the corresponding excitation either vanishes or changes abruptly in character at T/sub lambda/.

• Research Organization: Department of Physics, University of Delaware, Newark, Delaware 19716
• OSTI ID: 6592815
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:16; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COHERENT SCATTERING
DIFFRACTION
DISPERSION RELATIONS
EVEN-EVEN NUCLEI
FLUIDS
FORM FACTORS
HELIUM 4
HELIUM ISOTOPES
INELASTIC SCATTERING
ISOTOPES
LIGHT NUCLEI
LIQUIDS
MEDIUM PRESSURE
NEUTRON DIFFRACTION
NUCLEI
PARTICLE PROPERTIES
PHONONS
QUASI PARTICLES
ROTONS
SCATTERING
STABLE ISOTOPES
SUPERFLUIDITY
TEMPERATURE DEPENDENCE