Thermal conductivity and viscosity via phonon-phonon, phonon-roton, and roton-roton scattering in thin /sup 4/He films

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

DOI:https://doi.org/10.1103/PhysRevB.38.8838· OSTI ID:7086882

Um, C; Jun, C; Kahng, W; George, T F

The coefficients of the thermal conductivity (kappa) and first viscosity (eta) in thin helium films are evaluated explicitly as a function of temperature via phonon-phonon, phonon-roton, and roton-roton scattering. Above about 0.8 K, phonon-roton scattering and five-phonon processes are the main contributors to both coefficients. Below about 0.8 K, both coefficients increase exponentially with decreasing temperature. At temperatures below 0.3 K, kappa/sub ph/ has a T/sup -5/ dependence, while eta/sub ph/ shows exponential and T/sup -1/ dependencies. In the case of eta/sub ph/, the former is due to phonon-roton scattering and the latter originates from three-phonon processes. The coefficient kappa/sub r/ from roton-roton scattering varies as T/sup -1/, and the roton part eta/sub r/ of the first viscosity is independent of temperature.

• Research Organization: Department of Physics, College of Science, Korea University, Seoul 132, Korea
• OSTI ID: 7086882
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:13; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
EVEN-EVEN NUCLEI
FILMS
FLUIDS
HELIUM 4
HELIUM I
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LANDAU LIQUID HELIUM THEORY
LIGHT NUCLEI
NUCLEI
PHONONS
PHYSICAL PROPERTIES
QUANTUM FLUIDS
QUASI PARTICLES
ROTONS
STABLE ISOTOPES
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSPORT THEORY
VISCOSITY