Diffusive thermal conductivity of theA1-phase ofsuperfluid 3He at low temperatures

Abstract

The diffusive thermal conductivity tensor of theA1-phase ofsuperfluid 3He at low temperatures and melting pressure are calculated beyond the s–p approximation, byusing the Boltzmann equation approach. The interaction between normal–normal,normal–Bogoliubov and Bogoliubov–Bogoliubov quasiparticles in the collisionintegrals are considered for important scattering processes such as binaryprocess. At low temperatures, we show that the scattering between Bogoliubovand normal quasiparticles in binary processes plays an important role in theA1-phase, and Bogoliubov–Bogoliubov interaction is ignorable.We show that the two normal and superfluid components take part inelements of the diffusive thermal conductivity tensor differently. Weobtain the result that the elements of the diffusive thermal conductivities,Kxx,Kyy andKzz, areproportional to T−1, and also that the superfluid components of the diffusive thermal conductivity tensor, and , are proportional to T3 and T, respectively.