Ultrasonic attenuation in superconducting borocarbides YNi2B2C

Recently we have proposed s+g-wave superconductor in order to describe unusual superconductivity in borocarbides YNi2B2C and LuNi2B2C. In the present paper we study both the longitudinal and the transverse ultrasonic attenuation coefficients in the hydrodynamic limit. Indeed, such experiments have been reported very recently. The present model appears to describe the attenuation coefficients of L100, L001, T110 and T001 modes in the superconducting YNi2B2C very well. On the other hand, for L110 and T100 modes, the experimental results are somewhat different from the theoretical prediction