Electronic properties of chiral IrGe4 studied by angle resolved photoemission spectroscopy and band structure calculation

We have investigated band structure of chiral IrGe4 by means of angle-resolved photoemission spectroscopy (ARPES) and band structure calculation. The band structure calculation predicts Kramers-Weyl degeneracy at the time reversal invariant momentum points. Although IrGe4 does not have a well-defined cleavage plane, we could observe momentum-dependent ARPES intensity modulations by ARPES. The ARPES intensity near the Fermi level was enhanced around the M and K points where the Ge 4p bands are located at about 0.3 eV below the Fermi level both in the calculation and in the experiment. Although the overall band dispersion of the Ge 4p and Ir 5d bands agrees with the calculation, surface states between the Kramers-Weyl points are not clearly observed probably due to roughness of the fractured surface.