Study of cooperative phenomena - the Bose-Einstein condensation of /sup 4/He film and the Hubbard model of magnetism

Thesis/Dissertation · Mon Jan 01 00:00:00 EST 1979

OSTI ID:6048840

Mei, W N

A monolayer of /sup 4/He atoms is treated as a system of hard-sphere bosons in a thin film geometry, with a finite thickness. The method of pseudopotential is used to calculate first the energy spectrum, and then the Helmolz free energy and other thermodynamic functions of the system. It is found that Bose-Einstein condensation exists below a definite temperature. Much like a liquid-gas transition, the boson system displays a high temperature normal phase, a low temperature condensed superfluid phase and a coexistence region. In the present treatment, the minimum momentum associated with the finite thickness of monolayer is used as a parameter. We find that the transition temperature is linearly proportional to the density of the /sup 4/He film. After performing double-tangent construction of the Helmholz free energy curve we find for the specific heat a rounded peak at the transition temperature, in agreement with recent experiments. The ratio of the superfluid density at the transition point to the transition temperature is found to be essentially a constant.

• Research Organization: State Univ. of New York, Buffalo (USA)
• OSTI ID: 6048840
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HELIUM II
BOSE-EINSTEIN CONDENSATION
DENSITY
FILM FLOW
FREE ENERGY
MAGNETISM
PHASE TRANSFORMATIONS
SPECIFIC HEAT
THEORETICAL DATA
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
DATA
ENERGY
EVEN-EVEN NUCLEI
FLUID FLOW
FLUIDS
HELIUM 4
HELIUM ISOTOPES
INFORMATION
ISOTOPES
LIGHT NUCLEI
NUCLEI
NUMERICAL DATA
PHYSICAL PROPERTIES
QUANTUM FLUIDS
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
640450* - Fluid Physics- Superfluidity