Lead phthalocyanine (PbPc), a non-planar molecule, is studied on Pb(100) using scanning tunneling spectroscopy. A rigid shift of the molecular orbitals is found between molecules with the central Pb ion pointing to (PbPc↓) or away (PbPc↑) from the substrate and understood from the interaction between the molecules and their image charges. Inside the superconducting energy gap, Yu-Shiba-Rusinov (YSR) resonances are observed for PbPc↑ molecules in islands indicating the presence of a magnetic moment. Such bound states are neither present on PbPc↓ molecules nor isolated PbPc↑ or molecules that lost the Pb ion during deposition (H0Pc). The YSR energies vary depending on the orientation and type of the molecular neighbors. We analyze the role of the out-of-plane dipole moment of PbPc.
Cite
@article{arxiv.2402.08330,
title = {Making Closed-Shell Lead-Pthalocyanine Paramagnetic on Pb(100)},
author = {Jan Homberg and Alexander Weismann and Richard Berndt},
journal= {arXiv preprint arXiv:2402.08330},
year = {2024}
}