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

Journal Article · Tue Nov 01 00:00:00 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), Vol. 38:13
• Country of Publication: United States
• Language: English

Related Subjects

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