Formation of surface and quantum-well states in ultra thin pt films on the Au(111) surface

The electronic structure of the Pt/Au(111) heterostructures with a number of Pt monolayers n ranging from one to three is studied in the density-functional-theory framework. The calculations demonstrate that the deposition of the Pt atomic thin films on gold substrate results in strong modifications of the electronic structure at the surface. In particular, the Au(111) s-p-type Shockley surface state becomes completely unoccupied at deposition of any number of Pt monolayers. The Pt adlayer generates numerous quantum-well states in various energy gaps of Au(111) with strong spatial confinement at the surface. As a result, strong enhancement in the local density of state at the surface Pt atomic layer in comparison with clean Pt surface is obtained. The excess in the density of states has maximal magnitude in the case of one monolayer Pt adlayer and gradually reduces with increasing number of Pt atomic layers. The spin-orbit coupling produces strong modification of the energy dispersion of the electronic states generated by the Pt adlayer and gives rise to certain quantum states with a characteristic Dirac-cone shape.We acknowledge the Tomsk State University competitiveness programme (Project No. 8.1.01.2017) and partial support by the Saint Petersburg State University (Project No. 15.61.202.2015). I.V.S. acknowledges financial support from the Ministry of Education and Science of the Russian Federation within governmental program Megagrants (State Task No. 3.9003.2017/Π220 or 3.9003.2017/9.10). Y.M.K. acknowledges the Russian Foundation for Basic Research (Project No. 15-02-02717-a). E.V.C. acknowledges the Spanish Ministry of Science and Innovation (Grant No. FIS2016-75862-P).Peer Reviewe