# Tailored Spin Coupling of Single-Molecule Magnets with a Single Charge-Density-Wave Metal Layer

## TL;DR

Researchers explored how magnetic molecules interact with a special metal layer, revealing new ways to control quantum effects at the atomic scale.

## Contribution

The study demonstrates precise control of the Kondo effect in a single-layer charge-density-wave metal using molecular positioning.

## Key findings

- Kondo signatures were observed on specific adsorption sites of CoPc molecules on H-NbSe2.
- Four distinct configurations of CoPc molecules were identified based on their position relative to the NbSe2 lattice.
- Local magnetism was induced in the nonmagnetic NbSe2 layer through spin coupling with CoPc molecules.

## Abstract

The interplay between spin and charge can give rise to
remarkable
quantum states of matter. A celebrated example is the Kondo effect,
which occurs when localized magnetic impurities are screened by itinerant
electrons. While significant advances have been made in probing the
Kondo effect in systems consisting of magnetic impurities adsorbed
on conventional bulk metals, its manifestation on unconventional metals
with strong many-body interactions, particularly down to atomic-layer
thickness, has hitherto remained unexplored. Here we investigate the
charge and spin interaction between magnetic cobalt phthalocyanine
(CoPc) molecules acting as spin-bearing Kondo impurities and a single,
substrate supported layer of the charge-density-wave (CDW) metal H-NbSe2. Remarkably, we present unambiguous Kondo signatures on certain
adsorption sites. We identify four distinct configurations depending
on the position of the Co2+ ion relative to the atomic
lattice and the CDW superlattice of NbSe2. We show precise
control of the Kondo effect by reversible repositioning of the CoPc
molecule between the different positions. Our scanning tunneling microscopy
(STM) and spectroscopy (STS) measurements further reveal the symmetry
breaking of the Kondo resonance, indicating a pronounced magnetic
anisotropy in CoPc/NbSe2. More importantly, this interaction
can induce local magnetism into the nonmagnetic NbSe2 layer,
offering new possibilities for tailoring spin textures.