Spin-wave radiation from vortices in 3He−B
|Author:||Laine, S. M.1; Thuneberg, E. V.1|
1Nano and Molecular Systems Research Unit, University of Oulu, FI-90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 0.8 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2019092630083
American Physical Society,
|Publish Date:|| 2019-09-26
We consider a vortex line in the B phase of superfluid 3He under uniformly precessing magnetization. The magnetization exerts torque on the vortex, causing its order parameter to oscillate. These oscillations generate spin waves, which is analogous to an oscillating charge generating electromagnetic radiation. The spin waves carry energy, causing dissipation in the system. Solving the equations of spin dynamics, we calculate the energy dissipation caused by spin-wave radiation for arbitrary tipping angles of the magnetization and directions of the magnetic field, and for both vortex types of 3He-B. For the double-core vortex we also consider the anisotropy of the radiation and the dependence of the dissipation on twisting of the half cores. The radiated energy is compared with experiments in the midtemperature range T∼0.5Tc. The dependence of the calculated dissipation on several parameters is in good agreement with the experiments. Combined with numerically calculated vortex structure, the radiation theory produces the order of magnitude of the experimental dissipation. The agreement with the experiments indicates that spin-wave radiation is the dominant dissipation mechanism for vortices in superfluid 3He-B in the midtemperature range.
Physical review. B
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
114 Physical sciences
This work was financially supported by the Vilho, Yrjö, and Kalle Väisälä Foundation, the Jenny and Antti Wihuri Foundation, and the Oskar Öflunds Stiftelse sr.
© 2018 American Physical Society.