Collective modes and sound propagation in a magnetic field in superfluid /sup 3/He-B

Journal Article · Tue Apr 01 04:00:00 EST 1986 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00682064· OSTI ID:5611221

Shivaram, B S; Meisel, M W; Sarma, B K; Halperin, W P; Ketterson, J B

A high-resolution, ultrasonic (12-89 MHz) acoustic impedance technique has been used to investigate the order parameter collective modes in superfluid /sup 3/He-B over a pressure range of 0-15 bar and in magnetic fields up to 180 mT. In agreement with earlier experiments, the J = 2 real squashing mode has been observed to split into five components in small magnetic fields. However, contrary to earlier theoretical estimates, the Zeeman shifts have been found to become extremely nonlinear as the magnetic field is increased. The extent of this nonlinearity is largest at low pressures and at temperatures close to T/sub c/. In comparison with recent theoretical work, the nonlinear Zeeman shifts may be explained as a result of two effects. First, there is a significant distortion of the B-phase energy gap in large magnetic fields. Second, there is an important coupling between the J/sub z/ substates of the different J modes. In this sense the nonlinear evolution of the real squashing mode constitutes the observation of the Paschen-Back effect in /sup 3/He-B.

• Research Organization: Department of Physics and Astronomy and Materials Research Center, Northwestern University, Evanston, Illinois
• OSTI ID: 5611221
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 63:1; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COLLECTIVE EXCITATIONS
ENERGY-LEVEL TRANSITIONS
EVEN-ODD NUCLEI
EXCITATION
HELIUM 3
HELIUM 3 B
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC FIELDS
NONLINEAR PROBLEMS
NUCLEI
ORDER PARAMETERS
SOUND WAVES
STABLE ISOTOPES
ULTRASONIC WAVES
WAVE PROPAGATION
ZEEMAN EFFECT