Download all files (8.05 MB)

Collection

Citation

Description:

Frustrated spin systems, where competing interactions prevent conventional magnetic ordering, provide a platform for uncovering emergent quantum phases and exotic many-body phenomena. Particularly, low-dimensional and symmetric geometries without boundary conditions allow us to study the unconventional spin states. Here, we present S = 1/2 anti-ferromagnetic Heisenberg cyclic pentamer and hexamer via homocoupling of air-stable phenalenyl derivatives on Au(111). With a combination of scanning tunnelling microscopy/scanning tunnelling spectroscopy at 4.3 K and compre-hensive theoretical simulations, we found that while large magnetic exchange interactions exist in both rings, the pen-tamer features an increased geometric frustration of the system. This frustration induces rotational symmetry in the spin wavefunction, leading to a four-fold degenerate ground states of the pentamer. The interplay between molecular geometry and magnetic interactions creates the unique quantum spin environment. Our findings offer a powerful approach for constructing spin-frustrated molecular architectures, allowing precise control over quantum magnetic interactions.

Rights:

• Creative Commons BY Attribution 4.0 International
  

Keyword: scanning tunneling microscopy, quantum spin, spin-frustrated molecular, quantum magnetic interactions, scanning tunneling spectroscopy

Date published: 2025-07-30

Publisher: American Chemical Society (ACS)

Journal:

• Journal of the American Chemical Society (ISSN: 00027863) vol. 147 issue. 30 p. 26208-26217

Funding:

• Japan Society for the Promotion of Science 25H00422
• Research Council of Finland 346824
• Research Council of Finland 347319
• Research Council of Finland 35808
• Japan Society for the Promotion of Science 20H05865
• Japan Society for the Promotion of Science 22H00285
• Japan Society for the Promotion of Science 24H00459
• Japan Society for the Promotion of Science 24K21721
• Japan Society for the Promotion of Science 24KF0269
• Research Council of Finland 331342

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1021/jacs.5c03112

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-08-20 08:30:20 +0900

Published on MDR: 2025-08-20 08:24:23 +0900