Theory of spin-wave excitation in the spin-triplet superconducting state of SrRuO; Multi-band calculation

Nomura, Takuji; Hirashima, Dai*

We discuss possible collective spin-wave excitation in the spin-triplet superconducting state of the ruthenate superconductor SrRuO. Using a realistic multi-band electronic structure and the superconducting gap structure obtained by microscopic calculation, we calculate the in-plane spin susceptibility and obtain the collective spin excitation spectrum. Fluctuation effect of the triplet-pairing condensate on the in-plane susceptibility is taken into account. As a result from rotational symmetry breaking in spin space, collective spin excitation mode can appear in the in-plane spin susceptibility.