Momentum-selective orbital hybridisation

Nature Communications, vol. 13, pp. 5148

Abstract

When a molecule interacts chemically with a metal surface, the orbitals of the molecule hybridise with metal states to form the new eigenstates of the coupled system. Spatial overlap and energy matching are determining parameters of the hybridisation. However, since every molecular orbital does not only have a characteristic spatial shape, but also a specific momentum distribution, one may additionally expect a momentum matching condition; after all, each hybridising wave function of the metal has a defined wave vector, too. Here, we report photoemission orbital tomography measurements of hybrid orbitals that emerge from molecular orbitals at a molecule-on-metal interface. We find that in the hybrid orbitals only those partial waves of the original orbital survive which match the metal band structure. Moreover, we find that the conversion of the metal's surface state into a hybrid interface state is also governed by momentum matching constraints. Our experiments demonstrate the possibility to measure hybridisation momentum-selectively, thereby enabling deep insights into the complicated interplay of bulk states, surface states, and molecular orbitals in the formation of the electronic interface structure at molecule-on-metal hybrid interfaces.

Authors 9

1. Xiaosheng Yang Aachen Experimental Physics IV A

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Experimental Physics IV A, RWTH Aachen University, 52074, Aachen, Germany

   Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425, Jülich, Germany

   Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425, Jülich, Germany

   Jülich Aachen Research Alliance (JARA)–Fundamentals of Future Information Technology, 52425, Jülich, Germany

2. Matteo Jugovac

   Forschungszentrum Jülich · Elettra-Sincrotrone Trieste S.C.p.A.

   Affiliation as printed

   Elettra - Sincrotrone Trieste, S.S. 14 km 163.5, Basovizza, 34149, Trieste, Italy

   Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425, Jülich, Germany

3. Giovanni Zamborlini

   Forschungszentrum Jülich · TU Dortmund University

   Affiliation as printed

   Department of Physics, TU Dortmund University, Dortmund, Germany

   Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425, Jülich, Germany

4. Vitaliy Feyer

   Forschungszentrum Jülich · University of Duisburg-Essen

   Affiliation as printed

   Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, 47047, Duisburg, Germany

   Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425, Jülich, Germany

5. Georg Koller

   University of Graz · Nawi Graz

   Affiliation as printed

   Institute of Physics, University of Graz, NAWI Graz, 8010, Graz, Austria

6. Peter Puschnig

   University of Graz · Nawi Graz

   Affiliation as printed

   Institute of Physics, University of Graz, NAWI Graz, 8010, Graz, Austria

7. Serguei Soubatch

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425, Jülich, Germany

   Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425, Jülich, Germany

   Jülich Aachen Research Alliance (JARA)–Fundamentals of Future Information Technology, 52425, Jülich, Germany

8. Michael G. Ramsey

   University of Graz · Nawi Graz

   Affiliation as printed

   Institute of Physics, University of Graz, NAWI Graz, 8010, Graz, Austria. michael.ramsey@uni-graz.at

   Institute of Physics, University of Graz, NAWI Graz, 8010, Graz, Austria

9. Frank Stefan Tautz Aachen Experimental Physics IV A

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Experimental Physics IV A, RWTH Aachen University, 52074, Aachen, Germany. s.tautz@fz-juelich.de

   Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425, Jülich, Germany. s.tautz@fz-juelich.de

   Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425, Jülich, Germany. s.tautz@fz-juelich.de

   Experimental Physics IV A, RWTH Aachen University, 52074, Aachen, Germany

   Jülich Aachen Research Alliance (JARA)–Fundamentals of Future Information Technology, 52425, Jülich, Germany

   Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425, Jülich, Germany