Mahalingam Maniraj, Lu Lyu, Sina Mousavion, S. Becker, S. Emmerich, D. Jungkenn, D. L. Schlagel, T.A. Lograsso, Sudipta Roy Barman, Stefan Mathias, Benjamin Stadtmüller, Martin Aeschlimann
- Designing exotic structures in low dimensions is key in today’s quest to tailor novel quantum states
in materials with unique symmetries. Particularly intriguing materials in this regard are low
dimensional aperiodic structures with non-conventional symmetries that are otherwise forbidden
in translation symmetric crystals. In our work, we focus on the link between the structural and
electronic properties of aperiodically ordered aromatic molecules on a quasicrystalline surface,
which has largely been neglected so far. As an exemplary case, we investigate the self-assembly and
the interfacial electronic properties of the nano-graphene-like molecule coronene on the bulk
truncated icosahedral (i) Al–Pd–Mn quasicrystalline surface using multiple surface sensitive
techniques. We find an aperiodically ordered coronene monolayer (ML) film on the i-Al–Pd–Mn
surface that is characterized by the same local motifs of the P1 Penrose tiling model as the bare
i-Al–Pd–Mn surface. The electronic valence band structure of the coronene/i-Al–Pd–Mn system
is characterized by the pseudogap of the bare i-Al–Pd–Mn, which persists the adsorption of
coronene confirming the quasiperiodic nature of the interface. In addition, we find a newly formed
interface state of partial molecular character that suggests an at least partial chemical interaction
between the molecule and the quasicrystalline surface. We propose that this partial chemical
molecule–surface interaction is responsible for imprinting the quasicrystalline order of the surface
onto the molecular film.
