A high-resolution angle-resolved photoemission study of relativistic effects on the surface electronic structure of Cu(001)

Abstract A high-resolution angle-resolved photoemission study has located a second Cu(001) M surface state, having a binding energy of 2.11 eV, 65 meV below the d-band maximum. The dispersion of this state has been measured along the ∑ and Y surface Brillouin zone lines. Comparison with a projection of a relativistic band structure indicates that this state lies in an absolute spin-orbit gap along ∑ and the first quarter of the Y line from M . Beyond this point along Y it lies in an absolute d-d hybridisation gap. In addition, the dispersion of the well-known Y 2 Tamm surface state has been measured along Y for the first time.