We have investigated the bulk and surface electronic structure of pyrite-type ${\mathrm{CuSe}}_2$ by means of soft x-ray photoemission spectroscopy. The Cu $3d$ band around 2.5 eV below the Fermi level does not show Cu $2p\text{−}3d$ resonance indicating that the Cu $3d$ level is almost fully filled and the Cu valence is close to $+1$. The dispersions of the Cu $3d/\mathrm{Se}4p$ bands observed by angle-resolved measurements roughly follow slab calculations for (100) surface. The surface of pyrite-type ${\mathrm{CuSe}}_2$ harbors two-dimensional Dirac-like band dispersions at the corner of the surface Brillouin zone suggesting possible interplay between the surface/interface Dirac states and the exotic bulk electronic/lattice properties through the Cu $3d$-Se $4p$ interaction.

Close

PrevNext

View figure in article

• Charge dynamics
• Dirac fermions
• Chalcogenides
• Angle-resolved photoemission spectroscopy
• Band structure methods