High-resolution angle-resolved photoemission study of the heavy-fermion superconductor (formula presented)

We report high-resolution angle-resolved photoemission spectroscopy (HR ARPES) on single-crystal (Formula presented) together with a full-potential linearized augmented-plane-wave band-structure calculation for comparison. The experimental results show a narrow dispersionless U (Formula presented) band at (Formula presented) and highly dispersive Pt (Formula presented) bands at higher binding energies. The observed U (Formula presented) band shows a systematic intensity variation in accordance with the crystal momentum, but is much narrower than the calculation, while the Pt (Formula presented) bands show a good quantitative agreement between the experiment and calculation. The present HR-ARPES observation suggests a substantial renormalization effect of the U (Formula presented) band due to the strong correlation.