English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Tunable Spin–Superconductor Coupling of Spin 1/2 Vanadyl Phthalocyanine Molecules

MPS-Authors
/persons/resource/persons182904

Malavolti,  L.
Institute for Functional Matter and Quantum Technologies;
Dynamics of Nanoelectronic Systems, Independent Research Groups, Max Planck Institute for the Structure and Dynamics of Matter, Max Planck Society;
Max Planck Institute for Solid State Research;

/persons/resource/persons213992

Hänze,  M.
Institute for Functional Matter and Quantum Technologies;
Dynamics of Nanoelectronic Systems, Independent Research Groups, Max Planck Institute for the Structure and Dynamics of Matter, Max Planck Society;
Max Planck Institute for Solid State Research;

/persons/resource/persons182906

McMurtrie,  G.
Institute for Functional Matter and Quantum Technologies;
Dynamics of Nanoelectronic Systems, Independent Research Groups, Max Planck Institute for the Structure and Dynamics of Matter, Max Planck Society;
Max Planck Institute for Solid State Research;

/persons/resource/persons133858

Loth,  S.
Institute for Functional Matter and Quantum Technologies;
Dynamics of Nanoelectronic Systems, Independent Research Groups, Max Planck Institute for the Structure and Dynamics of Matter, Max Planck Society;
Max Planck Institute for Solid State Research;

External Resource
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
Citation

Malavolti, L., Briganti, M., Hänze, M., Serrano, G., Cimatti, I., McMurtrie, G., et al. (2018). Tunable Spin–Superconductor Coupling of Spin 1/2 Vanadyl Phthalocyanine Molecules. Nano Letters, 18(12), 7955-7961. doi:10.1021/acs.nanolett.8b03921.


Cite as: http://hdl.handle.net/21.11116/0000-0002-B83D-B
Abstract
Atomic-scale magnetic moments in contact with superconductors host rich physics based on the emergence of Yu–Shiba–Rusinov (YSR) magnetic bound states within the superconducting condensate. Here, we focus on a magnetic bound state induced into Pb nanoislands by individual vanadyl phthalocyanine (VOPc) molecules deposited on the Pb surface. The VOPc molecule is characterized by a spin magnitude of 1/2 arising from a well-isolated singly occupied dxy-orbital and is a promising candidate for a molecular spin qubit with long coherence times. X-ray magnetic circular dichroism (XMCD) measurements show that the molecular spin remains unperturbed even for molecules directly deposited on the Pb surface. Scanning tunneling spectroscopy and density functional theory (DFT) calculations identify two adsorption geometries for this “asymmetric” molecule (i.e., absence of a horizontal symmetry plane): (a) oxygen pointing toward the vacuum with the Pc laying on the Pb, showing negligible spin–superconductor interaction, and (b) oxygen pointing toward the Pb, presenting an efficient interaction with the Pb and promoting a Yu–Shiba–Rusinov bound state. Additionally, we find that in the first case a YSR state can be induced smoothly by exerting mechanical force on the molecules with the scanning tunneling microscope (STM) tip. This allows the interaction strength to be tuned continuously from an isolated molecular spin case, through the quantum critical point (where the bound state energy is zero) and beyond. DFT indicates that a gradual bending of the VO bond relative to the Pc ligand plane promoted by the STM tip can modify the interaction in a continuously tunable manner. The ability to induce a tunable YSR state in the superconductor suggests the possibility of introducing coupled spins on superconductors with switchable interaction.