Electron spin secluded inside a bottom-up assembled standing metal-molecule nanostructure

Physical Review Research, vol. 5

Abstract

Artificial nanostructures, fabricated by placing atoms or molecules as building blocks in well-defined positions, are a powerful platform in which quantum effects can be studied and exploited. In particular, they offer the opportunity to reduce the electronic interaction between large aromatic molecules and the underlying metallic substrate, if the manipulation capabilities of scanning tunneling microscopy to lift the molecule into an upright geometry on a pedestal of two metal atoms are used. Here, we report a strategy to study this interaction by investigating the Kondo effect. Measurements at millikelvin temperatures and in magnetic fields reveal that this bottom-up assembled standing metal-molecule nanostructure has an $S=1/2$ spin which is screened by substrate electrons, resulting in a Kondo temperature of only $291\ifmmode\pm\else\textpm\fi{}13$ mK. We extract its Land\'e $g$ factor and its exchange coupling $J\ensuremath{\rho}$ to the substrate, using a third-order perturbation theory in the weak-coupling and high-field regimes. We also show that the interaction between the scanning tunneling microscope tip and the molecule can tune the exchange coupling.

Authors 4

1. Taner Esat

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany

   Peter Grünberg Institute (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany

2. Markus Ternes Aachen Institute of Physics II B

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute of Physics II B, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany

   Peter Grünberg Institute (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany

3. Ruslan Temirov

   Forschungszentrum Jülich · University of Cologne · Jülich Aachen Research Alliance

   Affiliation as printed

   Institute of Physics II, University of Cologne, 50937 Cologne, Germany

   Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany

   Peter Grünberg Institute (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany

4. Frank Stefan Tautz Aachen Experimental Physics IV A

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Experimental Physics IV A, RWTH Aachen University, 52074 Aachen, Germany

   Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany

   Peter Grünberg Institute (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany