A Route Toward the On-Surface Synthesis of Organic Ferromagnetic Quantum Spin Chains

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Paschke, Fabian, Ortiz, Ricardo, Mishra, Shantanu, Vilas-Varela, Manuel, Albrecht, Florian, Peña, Diego, Melle-Franco, Manuel, Gross, Leo
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866915182737883136
author Paschke, Fabian
Ortiz, Ricardo
Mishra, Shantanu
Vilas-Varela, Manuel
Albrecht, Florian
Peña, Diego
Melle-Franco, Manuel
Gross, Leo
author_facet Paschke, Fabian
Ortiz, Ricardo
Mishra, Shantanu
Vilas-Varela, Manuel
Albrecht, Florian
Peña, Diego
Melle-Franco, Manuel
Gross, Leo
contents Engineering sublattice imbalance is an intuitive way to induce high-spin ground states in bipartite polycyclic conjugated hydrocarbons (PCHs). Such high-spin molecules can be employed as building blocks of quantum spin chains, which are outstanding platforms to study many-body physics and fundamental models in quantum magnetism. Recent reports on the bottom-up synthesis of antiferromagnetic molecular spin chains provided insights into paradigmatic quantum phenomena such as fractionalization. In contrast to antiferromagnetism, demonstration of ferromagnetic coupling between PCHs has been scarce. Previous attempts in this direction were limited by the formation of non-benzenoid rings leading to spin quenching, or the use of spacer motifs that considerably weaken the magnitude of ferromagnetic exchange. Here, we demonstrate the on-surface synthesis of short ferromagnetic spin chains based on dibenzotriangulene (DBT), a PCH with a triplet ground state. Our synthetic strategy centers on achieving a direct (that is, without a spacer motif) majority-minority sublattice coupling between adjacent units. This leads to a global sublattice imbalance in spin chains scaling with the chain length, and therefore a ferromagnetic ground state with a strong intermolecular ferromagnetic exchange. By means of scanning probe measurements and multiconfigurational quantum chemistry calculations, we analyze the electronic and magnetic properties of ferromagnetic dimers and trimers of DBT, and confirm their quintet and septet ground states, respectively, with an intermolecular ferromagnetic exchange of 7 meV. Furthermore, we elucidate the role of sublattice coupling on magnetism through complementary experiments on antiferromagnetic DBT dimers with majority-majority and minority-minority couplings. We expect our proof-of-principle study to provide impetus for the design of purely organic ferromagnetic materials.
format Preprint
id arxiv_https___arxiv_org_abs_2412_11884
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Route Toward the On-Surface Synthesis of Organic Ferromagnetic Quantum Spin Chains
Paschke, Fabian
Ortiz, Ricardo
Mishra, Shantanu
Vilas-Varela, Manuel
Albrecht, Florian
Peña, Diego
Melle-Franco, Manuel
Gross, Leo
Mesoscale and Nanoscale Physics
Chemical Physics
Engineering sublattice imbalance is an intuitive way to induce high-spin ground states in bipartite polycyclic conjugated hydrocarbons (PCHs). Such high-spin molecules can be employed as building blocks of quantum spin chains, which are outstanding platforms to study many-body physics and fundamental models in quantum magnetism. Recent reports on the bottom-up synthesis of antiferromagnetic molecular spin chains provided insights into paradigmatic quantum phenomena such as fractionalization. In contrast to antiferromagnetism, demonstration of ferromagnetic coupling between PCHs has been scarce. Previous attempts in this direction were limited by the formation of non-benzenoid rings leading to spin quenching, or the use of spacer motifs that considerably weaken the magnitude of ferromagnetic exchange. Here, we demonstrate the on-surface synthesis of short ferromagnetic spin chains based on dibenzotriangulene (DBT), a PCH with a triplet ground state. Our synthetic strategy centers on achieving a direct (that is, without a spacer motif) majority-minority sublattice coupling between adjacent units. This leads to a global sublattice imbalance in spin chains scaling with the chain length, and therefore a ferromagnetic ground state with a strong intermolecular ferromagnetic exchange. By means of scanning probe measurements and multiconfigurational quantum chemistry calculations, we analyze the electronic and magnetic properties of ferromagnetic dimers and trimers of DBT, and confirm their quintet and septet ground states, respectively, with an intermolecular ferromagnetic exchange of 7 meV. Furthermore, we elucidate the role of sublattice coupling on magnetism through complementary experiments on antiferromagnetic DBT dimers with majority-majority and minority-minority couplings. We expect our proof-of-principle study to provide impetus for the design of purely organic ferromagnetic materials.
title A Route Toward the On-Surface Synthesis of Organic Ferromagnetic Quantum Spin Chains
topic Mesoscale and Nanoscale Physics
Chemical Physics
url https://arxiv.org/abs/2412.11884