Thermal Conductivity and Ultrasonic Attenuation in Clean Type-II Superconductors

Abstract

We calculate the thermal conductivity and low-frequency ultrasonic attenuation in clean type-II superconductors in the high-field region. Use is made of a Green's function due to Brandt, Pesch, and Tewordt which enables accurate calculation of the transport properties in the vicinity of the upper critical field. It is shown that in the low-temperature limit the transport coefficients are simple functions of a single parameter $\mu =2\mathrm{}\sqrt{\pi }{\left(\frac{\Delta }{k_c{v}_F}\right)}^2{k}_{c}l$, where ${\Delta }^2$ is the spatial average of the square of the order parameter, $k_c$ is the reciprocal-lattice vector of the vortex lattice, $v_F$ is the Fermi velocity, and $l$ is the electronic mean free path.