Changing the Interaction of a Single-Molecule Magnetic Moment with a Superconductor

Stefan Schulte; Nicolas Néel; Levente Rózsa; Krisztián Palotás; Jörg Kröger

doi:10.1021/acs.nanolett.2c03952

Changing the Interaction of a Single-Molecule Magnetic Moment with a Superconductor

Nano Lett. 2023 Feb 22;23(4):1622-1628. doi: 10.1021/acs.nanolett.2c03952. Epub 2023 Jan 5.

Authors

Stefan Schulte^{1

2

3}, Nicolas Néel¹, Levente Rózsa⁴, Krisztián Palotás^{5

6

7}, Jörg Kröger¹

Affiliations

¹ Institut für Physik, Technische Universität Ilmenau, D-98693Ilmenau, Germany.
² Peter Grünberg Institut, Forschungszentrum Jülich, D-52425Jülich, Germany.
³ II. Physikalisches Institut, Universität zu Köln, D-50923Cologne, Germany.
⁴ Fachbereich Physik, Universität Konstanz, D-78457Konstanz, Germany.
⁵ Department of Theoretical Solid State Physics, Institute for Solid State Physics and Optics, Wigner Research Center for Physics, H-1121Budapest, Hungary.
⁶ ELKH-SZTE Reaction Kinetics and Surface Chemistry Research Group, University of Szeged, H-6720Szeged, Hungary.
⁷ Department of Theoretical Physics, Institute of Physics, Budapest University of Technology and Economics, H-1111Budapest, Hungary.

PMID: 36603183
DOI: 10.1021/acs.nanolett.2c03952

Abstract

The exchange interaction of a brominated Co-porphyrin molecule with the Cooper pair condensate of Pb(111) is modified by reducing the Co-surface separation. The stepwise dehalogenation and dephenylation change the Co adsorption height by a few picometers. Only the residual Co-porphine core exhibits a Yu-Shiba-Rusinov bound state with low binding energy in the Bardeen-Cooper-Schrieffer energy gap. Accompanying density functional calculations reveal that the Co $d_{z^{2}}$ orbital carries the molecular magnetic moment and is responsible for the intragap state. The calculated spatial evolution of the Yu-Shiba-Rusinov wave function is compatible with the experimentally observed oscillatory attenuation of the electron-hole asymmetry with increasing lateral distance from the magnetic porphine center.

Keywords: Scanning tunneling microscopy and spectroscopy; Yu-Shiba-Rusinov bound state; density functional theory; magnetic exchange interaction; single-molecule chemical reaction; superconductivity.