Tuning Molecule-Mediated Spin Coupling in Bottom-Up-Fabricated Vanadium-Tetracyanoethylene Nanostructures

ORAL

Abstract

We have fabricated hybrid magnetic complexes from vanadium atoms and tetracyanoethylene (TCNE) ligands via atomic manipulation with a cryogenic scanning tunneling microscope. Using tunneling spectroscopy we observe spin-polarized molecular orbitals as well as a structure-dependent Kondo resonance. For complexes having two V atoms, the Kondo behavior can be switched on and off by a minute structural change, even as the spin-containing orbitals remain unchanged. This can be explained by variable spin-spin (i.e., V-V) ferromagnetic exchange coupling through the TCNE molecule, as supported by density functional calculations. These findings offer a new route for designing molecule-based magnetic nanostructures with tunable spin-spin exchange coupling.

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Authors

  • Xiaowei Zhang

    • University of California, Berkeley and Lawrence Berkeley National Laboratory

  • Daniel Wegner

    • University of California, Berkeley and Lawrence Berkeley National Laboratory

  • Ryan Yamachika

    • University of California, Berkeley and Lawrence Berkeley National Laboratory

  • Yayu Wang

    • University of California, Berkeley and Lawrence Berkeley National Laboratory

  • Tunna Baruah

    • University of Texas, El Paso

  • Mark Pederson

    • Naval Research Laboratory

  • Bart Bartlett

    • University of California, Berkeley

  • Jeffrey Long

    • University of California, Berkeley

  • Michael Crommie

    • University of California, Berkeley and Lawrence Berkeley National Laboratory