Quasi one-dimensional electronic states of alkali metal chains assembled on the InAs(110) surface

We investigate the electronic band dispersion associated to alkali metal chains assembled on the InAs(110) surface by angular-resolved photoelectron spectroscopy. The Cs and K atomic chains induce occupied electronic states with twofold symmetry and narrow bandwidth along the chain direction, showing a quasi-one-dimensional electronic character. The insulating character and the narrow bandwidth of the alkali-induced state suggest the relevance of electron correlation effects in the description of alkali-induced electronic-state dispersion.