Séminaires CINaM

lundi 19 juin 2023 à 11h00

CINaM - Salle Raymond Kern

Prof. Ernst Meyer

Department of Physics, University of Basel, CH-4056 Basel, Switzerland

From nanoribbons to supramolecular electron spin lattices: A scanning probe microscopy study combined with on-surface chemistry

On-surface chemistry is used to assemble polymeric wires [1,2], nanoribbons [3] as well as 2d- molecular networks [4]. Pulling of wires and ribbons is used to investigate the lateral motion as well the detachment of individual sub-units. The motion of graphene nanoribbons shows evidence of superlubricity. Sequential bending and twisting around single C-C bonds is observed in the case of poly- pyrenylene chains. 2d-molecular networks have promising electrical and magnetic properties as indicated by the formation of flat bands. In the case of the assembly of tetrabromo-1,3,6,8 tetraazapyrene (TBTAP) on Pb(111), neighboring rows of radicals and neutral molecules are observed [5]. Discharging of molecules is found by the application of positive voltages, where the formation of Coulomb blockade rings is observed. In contrast to a simple superposition of rings as expected for non- interacting quantum dots, their fusion is observed, which indicates a cascade discharge and thus a manifestation of electron correlation in the supramolecular assembly. Charged molecules host spin 1⁄2 electrons, which is confirmed by high resolution dI/dV spectroscopy, where Yu-Shiba-Rusinov (YSR) states in the superconductive gap are observed. Low energy modes are observed at the rim of molecular islands, which indicates the existence of topological edge states.

[1] R. Pawlak, J.G. Vilhena, P. D’Astolfo, X. Liu, G. Prampolini, T. Meier, Th. Glatzel, J.A. Lemkul, R. Häner, S. Decurtins, A. Baratoff, R. Perez, S.-X. Liu, E. Meyer, Nano Lett. , (20), (2020), 652-657.

[2] J. G. Vilhena, Remy Pawlak, P. D’Astolfo, X. Liu, E. Gnecco , M. Kisiel, T. Glatzel, R. Perez, R. Häner, S. Decurtins, A. Baratoff, G. Prampolini , S.-X. Liu and E. Meyer, Phys. Rev. Lett. 128, 216102 (2022)

[3] R. Pawlak, X. Liu, S. Ninova, P. D’Astolfo, C. Drechsel, S. Sangtarash, R. Häner, S. Decurtins, H. Sadeghi, C. J. Lambert, U. Aschauer, S-X. Liu, E. Meyer, Journal of the American Chemical Society, 142, (29), (2020), 12568-12573.

[4] R. Pawlak, X. Liu, S. Ninova, P. DAstolfo, C. Drechsel, J.-C. Liu, R. Häner, S. Decurtins, U. Aschauer, S.-X. Liu, and E. Meyer, Angew. Chem. Int. Ed., 60, (15), (2021), 8370-8375

[5] R. Pawlak et al. to be published (2023).


Séminaire interne: Brigino Ralahy, IMMF

TitreFluorinated dendrimer for 19F MRI-based theranostic.


Invitation : Entrée libre