Abstract and subjects
We report on low-temperature thermal conductivity of the noncentrosymmetric superconductor LaRhSi3 (T-c = 2.3 K), which is a paramagnetic analog of the pressure-induced superconductor CeRhSi3. In the normal state (either in zero field above T-c, or in magnetic field above H-c2), the thermal conductivity kappa is mostly due to electrons, and shows a nearly T-linear dependence. In the superconducting state, kappa decreases exponentially below T-c, and crosses over to kappa proportional to T-2 behavior at T << T-c. The temperature dependence of thermal conductivity of LaRhSi3 is similar to that of a number of conventional s-wave superconductors. The field dependence of the residual linear term kappa(0)/T as a function of magnetic field suggests that LaRhSi3 has no nodes in the superconducting gap.