Spectroscopic manifestation of mass renormalization in a layered 4d-electron superconductor Sr₂RuO₄

Recently discovered layered-perovskite superconductor Sr2RuO4 shows significant spectral weight redistribution in its low energy photoemission spectrum. This suggests the existence of strong electron correlation in the system. Renormalized mass is estimated by the phenomenological analysis of the spectrum. The importance of a momentum-dependent part of the self-energy is discussed.