Order-parameter collective modes in /sup 3/He-A and their effect on nuclear magnetic resonance (NMR) and ultrasonic attenuation

Journal Article · Thu Mar 01 04:00:00 EST 1979 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00114937· OSTI ID:6079358

Teword, L; Schopohl, N

A generalization of our previous microscopic theory is used to derive the spin and density correlation functions for the Anderson--Brinkman--Morel (ABM) state. The coupling of the 18 fluctuation components of the order parameter due to the nuclear dipole interaction is taken into accountrigorously. The results are valid for arbitary temperature, frequency, wave number (with q parallel to the anisotropy axis), and magnetic field. Damping by pari-breaking processes is calculated explicity; however, quasiparticle collisions are neglected. The frequencies of the clapping modes that couple to spin, and the frequencies of the flapping modes that couple to density, are found to split in a magnetic field. Near T/sub c/ the linewidth of the clapping mode and, at low T, the linewidth of the normal-flapping mode become small while the linewidth of the super-flapping mode is broad at all temperatures. The linewidth of the transverse NMR and the ultrasound attenuation coefficient, considered as functions of temperature, exhibit pronounced peaks at low temperatures. These arise from a coupling, induced by the dipole interaction, between spin or density fluctuations and the normal-flapping mode. Our results for the linewidth and line shift of the longitudinal NMR at low temperatures due to orbital effects are in agreement with results of Combescot.

• Research Organization: Abteilung fuer Theoretische Festkoerperphysik, Universitaet Hamburg, Hamburg, Germany
• OSTI ID: 6079358
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 34:5; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
CORRELATION FUNCTIONS
EVEN-ODD NUCLEI
FUNCTIONS
HELIUM 3
HELIUM 3 A
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORDER PARAMETERS
PARTICLE PROPERTIES
RESONANCE
SOUND WAVES
SPIN
STABLE ISOTOPES
ULTRASONIC WAVES