Electronic structure of BaNi2P2 observed by angle-resolved photoemission spectroscopy
Abstract
We have performed an angle-resolved photoemission spectroscopy (ARPES) study of BaNi2P2 which shows a superconducting transition at Tc 2.5 K. We observed hole and electron Fermi surfaces (FSs) around the Brillouin zone center and corner, respectively, and the shapes of the hole FSs dramatically changed with photon energy, indicating strong three-dimensionality. The observed FSs are consistent with band-structure calculation and de Haas-van Alphen measurements. The mass enhancement factors estimated in the normal state were m*/mb ≤ 2, indicating weak electron correlation compared to typical iron-pnictide superconductors. An electron-like Fermi surface around the Z point was observed in contrast with BaNi2As2 and may be related to the higher Tc of BaNi2P2.