Experimental determination of the /sup 3/He-quasiparticle excitation spectrum for dilute solutions of /sup 3/He in superfluid /sup 4/He

Journal Article · Mon Oct 01 04:00:00 EDT 1979 · Phys. Rev., B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.20.2643· OSTI ID:5753774

Greywall, D S

High-precision measurements of the second-sound velocity in /sup 3/He-/sup 4/He solutions with /sup 3/He molar concentrations, X, of up to 0.01 were made in the temperature range form 40 mK to T/sub lambda/(X). From the data obtained below 1 K, values of the /sup 3/He contribution, rho/sub n/3, to the normal-fluid density were extracted. A quasiparticle spectrum was found, using a computer fitting routine, which is consistent with both these rho/sub n/3 data and with previously reported specific-heat results. This spectrum shows significant deviations from quadratic behavior only for wave numbers greater than about 0.6 A/sup -1/ and is not in quantitative agreement with any of the previously proposed /sup 3/He excitation spectra. The effective mass of the quasiparticles determined from the rho/sub n/3 data (X,T..-->..0) is 2.34m/sub 3/, which is in good agreement with other experiments. However, the effective mass associated with the normal-fluid density (T..-->..0) is found to increase with increasing X. This is contrary to the expected result.

• Research Organization: Bell Laboratories, Murray Hill, New Jersey 07974
• OSTI ID: 5753774
• Journal Information: Phys. Rev., B: Condens. Matter; (United States), Journal Name: Phys. Rev., B: Condens. Matter; (United States) Vol. 20:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DISPERSIONS
EFFECTIVE MASS
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXCITATION
HELIUM 3
HELIUM 4
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MASS
MIXTURES
NUCLEI
PRESSURE DEPENDENCE
QUASI PARTICLES
SECOND SOUND
SOLUTIONS
STABLE ISOTOPES
SUPERFLUIDITY
TEMPERATURE DEPENDENCE