Shear viscosity of the A₁-phase of superfluid³He

Abstract

Abstract:The scattering processes between the quasiparticles in spin-up superfluid with the

Quasiparticle relaxation rate and shear viscosity of superfluid -A1 at low temperatures

“…It is noted that this is the same procedure applied for the results near c T [8]. It is interesting to mention that interaction between superfluid and normal fluid in the calculation of the transition probabilities is distinct, whereas the contribution from the interaction between Bogoliubov quasiparticles at low temperatures is negligible.…”

“…This can be considered as another result of the paper. Our results of quasiparticle relaxation rates can be used for calculation of other transport coefficients of superfluid He noted that s-approximation, s-p approximation, forward scattering approximation and so on [6,12] have been used to express the singlet and triplet QSA, although we here (and in [8,10]) have used Pfitzner procedure to calculate them. Of course, for a system as dense as He 3 there is no physical reason to expect the contribution from higher partial waves in QSA to be negligible.…”

Application of Boltzmann Equation on Spin Diffusion of Ferromagnetic Superfluid 3He: Near Critical Temperature

“…The transport properties such as the spin diffusion coefficients in the anisotropic A 1 -phase are highly desirable [6,22]. Some of transport coefficients of A 1 -phase have been derived both theoretically and experimentally; for example, viscosity at low temperatures and near critical temperature has been theoretically obtained [23][24][25][26] and a number of viscosity measurements have been carried out in a variety of high magnetic fields [27]. Also, thermal conductivity of A 1 -phase at low temperatures has been calculated theoretically, and as far as I am informed, there has been no data available about thermal conductivity of A 1 -phase [26,28,29] thus far.…”

“…'Bogoliubov quasiparticles') go to the superfluid state, and all quasiparticles with spin down stay in the normal state as presumed in Refs. [23][24][25][26][28][29][30][31]. In superfluids, unlike in the normal Fermi liquid, the number of quasiparticles is nonconservational.…”

“…Afterward, pressure dependence of spin diffusion change will be obtained. It should be noted that near its superfluid transition temperature, temperature dependence of spin diffusion of A 1 -phase as shear viscosity of B-phase [40] and A 1 -phase [25] is proportional to the magnitude of the energy gap (which is proportional to (1 − (T /T c↑ )) 1/2 ). This result is expected, because in the calculation of transport properties, the change of the first order of energy gap is important.…”