Theory of the temperature dependence of spatial correlations in liquid /sup 4/He

Journal Article · Sun Feb 01 04:00:00 EST 1981 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.23.1129· OSTI ID:6981060

Gaglione, G; Masserini, G L; Reatto, L

The temperature dependence of the structure factor S(k,T) of liquid /sup 4/He is studied on the basis of a model density matrix based on the elementary excitation picture and with roton excitations described in terms of the Feynman wave function. S(k,T) is constructed starting from the experimental low-temperature S(k), the energy spectrum epsilon/sub k/(T), and the linewidth delta/sub k/(T). No assumption is needed on the form of the Hamiltonian. The main peak of S(k,T) has an anomalous behavior, it increases its height and becomes sharper as the temperature is increased; this is due to thermal population of roton states that causes an enhancement of the short-range order. This anomalous behavior ends slightly above T/sub lambda/ when rotons become overdamped. Our result is in good quantitative agreement with experiment. This temperature effect becomes stronger at high density.

• Research Organization: Istituto di Fisica dell'Universita and Gruppo Nazionale di Struttura della Materia del Consiglio Nazionale delle Ricerche, via Celoria 16, Milano, Italy
• OSTI ID: 6981060
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 23:3; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DENSITY MATRIX
DISTRIBUTION FUNCTIONS
ENERGY SPECTRA
EVEN-EVEN NUCLEI
FEYNMAN GAS MODEL
FLUIDS
FUNCTIONS
HELIUM 4
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
LINE WIDTHS
LIQUIDS
MATHEMATICAL MODELS
MATRICES
NUCLEI
PARTICLE MODELS
PERTURBATION THEORY
QUASI PARTICLES
ROTONS
SPECTRA
STABLE ISOTOPES
STATISTICAL MODELS
STRUCTURE FACTORS
TEMPERATURE DEPENDENCE