We show that, although the equilibrium band dispersion of the Shockley-type surface state of two-dimensional Au(111) quantum films grown on W(110) does not deviate from the expected free-electron-like behavior, its nonequilibrium energy-momentum dispersion probed by time- and angle-resolved photoemission exhibits a remarkable kink above the Fermi level due to a significant enhancement of the effective mass. The kink is pronounced for certain thicknesses of the Au quantum well and vanishes in the very thin limit. [...]

We investigate the electronic and vibrational properties of bottom-up synthesized aligned armchair graphene nanoribbons of N = 7 carbon atoms width periodically doped by substitutional boron atoms (B-7AGNRs). Using angle-resolved photoemission spectroscopy and density functional theory calculations, we find that the dopant-derived valence and conduction band states are notably hybridized with electronic states of Au substrate and spread in energy. [...]

Using spin- and angle-resolved photoemission spectroscopy and relativistic many-body calculations, we investigate the evolution of the electronic structure of (Bi1−xInx)2Se3 bulk single crystals around the critical point of the trivial to topological insulator quantum-phase transition. By increasing x, we observe how a surface gap opens at the Dirac point of the initially gapless topological surface state of Bi2Se3, leading to the existence of massive fermions. [...]

To enhance the spin–orbit interaction in graphene by a proximity effect without compromising the quasi-free-standing dispersion of the Dirac cones means balancing the opposing demands for strong and weak graphene–substrate interaction. So far, only the intercalation of Au under graphene/Ni(1 1 1) has proven successful, which was unexpected since graphene prefers a large separation (~$3.3~{\mathring{\rm A}}$ ) from a Au monolayer in equilibrium. [...]

Topologically nontrivial states reveal themselves in strongly spin-orbit coupled systems by Dirac cones. However, their appearance is not a sufficient criterion for a topological phase. [...]