Frustrated magnetic interactions in a cyclacene crystal
| Autor: | R. Ortiz, J. C. Sancho-García, J. Fernández-Rossier |
|---|---|
| Přispěvatelé: | Universidad de Alicante. Departamento de Física Aplicada, Universidad de Alicante. Departamento de Química Física, Grupo de Nanofísica, Química Cuántica |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Cyclacene crystal
Physics and Astronomy (miscellaneous) Condensed Matter - Mesoscale and Nanoscale Physics Física de la Materia Condensada Física Aplicada Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Magnetism Density functional theory FOS: Physical sciences General Materials Science Química Física |
| Zdroj: | RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) |
| Popis: | We study the emergence of magnetism and its interplay with structural properties in a two-dimensional molecular crystal of cyclacenes, using density functional theory (DFT). Isolated cyclacenes with an even number of fused benzenes host two unpaired electrons in two topological protected zero modes, at the top and bottom carbon rings that form the molecule. We show that, in the gas phase, electron repulsion promotes an open-shell singlet with strong intramolecular antiferromagnetic exchange. We consider a closed packing triangular lattice crystal phase and we find a strong dependence of the band structure and magnetic interactions on the rotation angle of the cyclacenes with respect to the crystal lattice vectors. The orientational ground state maximizes the intermolecular hybridization, yet local moments survive. Intermolecular exchange is computed to be antiferromagnetic, and DFT predicts a broken symmetry 120∘ spin phase reflecting the frustration of the intermolecular spin coupling. Thus, the cyclacene crystal realizes a bilayer of two antiferromagnetically coupled S = 1/2 triangular lattices. Our results provide a bottom-up route towards carbon based strongly correlated platforms in two dimensions. We acknowledge funding support from Ministry of Science and Innovation of Spain (Grants No. PID2019-106114GB-I00 and No. PID2019-109539GB), Generalitat Valenciana and Fondo Social Europeo (Grant No. ACIF/2018/175), Generalitat Valenciana (Grant No. Prometeo2017/139), and FEDER/Junta de Andalucía Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Grant No. PY18-4834. |
| Databáze: | OpenAIRE |
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