摘要
The electronic surface states on Mo(110) have been investigated using time-of-flight momentum microscopy with synchrotron radiation (h nu = 35 eV). This novel angle-resolved photoemission approach yields a simultaneous acquisition of the E-vs-k spectral function in the full surface Brillouin zone and several eV energy interval. (k(x),k(y),E-B)-maps with 3.4 angstrom(-1) diameter reveal a rich structure of d-like surface resonances in the spin-orbit induced partial band gap. Calculations using the one-step model in its density matrix formulation predict an anomalous state with Dirac-like signature and Rashba spin texture crossing the bandgap at (Gamma) over bar and E-B = 1.2 eV. The experiment shows that the linear dispersion persists away from the (Gamma) over bar -point in an extended energy- and k(parallel to)-range. Analogously to a similar state previously found on W(110) the dispersion is linear along (H) over bar - (Gamma) over bar- (H) over bar and almost zero along (N) over bar - (Gamma) over bar - (N) over bar. The similarity is surprising since the spin-orbit interaction is 5 times smaller in Mo. A second point with unusual topology is found midway between (Gamma) over bar and (N) over bar. Band symmetries are probed by linear dichroism.
- 出版日期2015-12