Designer spin order in diradical nanographenes

Abstract

The magnetic properties of carbon materials are at present the focus of an intense research effort in physics, chemistry and materials science due to their potential applications in spintronics and quantum computations. Although the presence of spins in open-shell nanographenes has been recently confirmed, the ability to control magnetic coupling sign has remained elusive, but the most desirable. Here, we demonstrate an effective approach of engineering magnetic ground states in atomically precise open-shell bipartite/nonbipartite nanographenes using combined scanning probe techniques and mean-field Hubbard model calculations. The magnetic coupling sign between two spins has been controlled via breaking bipartite lattice symmetry of nanographenes. In addition, the exchange-interaction strength between two spins has been widely tuned by finely tailoring their spin density overlap, realizing a large exchange-interaction strength of 42 meV. Our demonstrated method provides ample opportunities for designer above-room-temperature magnetic phases and functionalities in graphene nanomaterials.

18 pages, 4 figures

References in corpus (8)

• Half-Metallic Graphene Nanoribbons
• Magnetism in Graphene Induced by Single-Atom Defects
• Emergence of magnetism in graphene materials and nanostructures
• Magnetism in graphene nano-islands
• Magnetic Correlations at Graphene Edges
• Atomic-scale control of graphene magnetism using hydrogen atoms
• Vacancy induced magnetism in graphene and graphene ribbons
• Unconventional and Exotic Magnetism in Carbon-Based Structures and Related Materials

Cited by in corpus (11)

• Magnetic Interactions Between Radical Pairs in Chiral Graphene Nanoribbons
• Building spin-1/2 antiferromagnetic Heisenberg chains with diaza-nanographenes
• Addressing electron spins embedded in metallic graphene nanoribbons
• Renormalization of spin excitations and Kondo effect in open shell nanographenes
• Fabrication of Spin-1/2 Heisenberg Antiferromagnetic Chains via Combined On-surface Synthesis and Reduction for Spinon Detection
• Broken-symmetry magnetic phases in two-dimensional triangulene crystals
• On-surface Synthesis of a Ferromagnetic Molecular Spin Trimer
• Triangle Counting Rule: An Approach to Forecast the Magnetic Properties of Benzenoid Polycyclic Hydrocarbons
• Quantum phase transition in magnetic nanographenes on a lead superconductor
• Elucidating the molecular orbital dependence of the total electronic energy in multireference problems
• A Route Toward the On-Surface Synthesis of Organic Ferromagnetic Quantum Spin Chains