Atomic-scale control of spin transport in exchange-coupled molecules
Abstract
Spin transport between coupled spins is governed by tunneling and exchange interactions, yet their microscopic relation in real space has remained experimentally elusive. To address this, we functionalize the tip of a scanning tunneling microscope with a single molecule and use it as a movable spin sensor positioned above a second molecule on a ferromagnetic surface, forming an exchange-coupled molecular junction. From the same spectroscopic dataset, we independently extract the junction conductance, exchange coupling, and spin polarization with atomic-scale resolution. Conductance and exchange display nearly identical spatial dependences, consistent with a minimal Hubbard description in which both are governed by the same hopping matrix between the molecular frontier orbitals. In contrast, the spin polarization depends on the orbital composition and the relative weight of the resulting transport channels. These results establish a real-space connection between tunneling, exchange, and spin transport in magnetically coupled molecules.
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BibTeX
@misc{fetida2026atomicscale,
title = {{Atomic-scale control of spin transport in exchange-coupled molecules}},
author = {A. Fétida and R. Robles and F. Scheurer and M. Romeo and J. Kröger and N. Lorente and L. Limot},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.37299},
eprint = {2609.37299},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.37299},
}
RIS
TY - UNPB
TI - Atomic-scale control of spin transport in exchange-coupled molecules
AU - A. Fétida
AU - R. Robles
AU - F. Scheurer
AU - M. Romeo
AU - J. Kröger
AU - N. Lorente
AU - L. Limot
PY - 2026
DA - 2026/09/29
PB - arXiv
DO - 10.48550/arxiv.2609.37299
UR - https://arxiv.org/abs/2609.37299
AB - Spin transport between coupled spins is governed by tunneling and exchange interactions, yet their microscopic relation in real space has remained experimentally elusive. To address this, we functionalize the tip of a scanning tunneling microscope with a single molecule and use it as a movable spin sensor positioned above a second molecule on a ferromagnetic surface, forming an exchange-coupled molecular junction. From the same spectroscopic dataset, we independently extract the junction conductance, exchange coupling, and spin polarization with atomic-scale resolution. Conductance and exchange display nearly identical spatial dependences, consistent with a minimal Hubbard description in which both are governed by the same hopping matrix between the molecular frontier orbitals. In contrast, the spin polarization depends on the orbital composition and the relative weight of the resulting transport channels. These results establish a real-space connection between tunneling, exchange, and spin transport in magnetically coupled molecules.
ER -