Low Temperature Limit of Stability of Coherent Precession of Spin in the Superfluid 3He-B

TL;DR

This paper investigates the stability of coherent spin precession in superfluid 3He-B at low temperatures, identifying the causes of instability and calculating the temperature limit for stable precession.

Contribution

It provides a theoretical analysis of the instability mechanisms and determines the minimum temperature for stable spin precession in superfluid 3He-B.

Findings

Instability arises from anisotropy and dipole interactions.

Maximum growth rate of spin wave amplitudes is calculated.

Minimum temperature for stable precession is estimated.

Abstract

It is shown that instability of homogeneous precession is caused by combined effect of anisotropy of spin wave velocities and dipole interaction. In the principal order on the ratio of the Leggett frequency to the Larmor frequency the increments of growth of spin wave amplitudes are found. The magnitude of the maximum increment for all deviation angles of spin from its equilibrium orientation is calculated. The estimation is made of the minimum temperature down to which the precession is stable.