2025-03-03 物質・材料研究機構
＜関連情報＞
- https://www.nims.go.jp/press/2025/03/202503030.html
- https://www.science.org/doi/10.1126/sciadv.ads1641
ハイゼンベルグスピン1/2反強磁性分子鎖の表面合成 On-surface synthesis of Heisenberg spin-1/2 antiferromagnetic molecular chains
Kewei Sun, Nan Cao, Orlando J. Silveira, Adolfo O. Fumega, […], and Shigeki Kawai
Science Advances Published:28 Feb 2025
DOI:https://doi.org/10.1126/sciadv.ads1641
Abstract
Magnetic exchange interactions between localized spins in π-electron magnetism of carbon-based nanostructures have attracted tremendous interest due to their great potential for nano spintronics. Unique many-body quantum characteristics, such as gaped excitations, strong spin entanglement, and fractionalized excitations, have been demonstrated, but the spin-1/2 Heisenberg model with a single antiferromagnetic coupling J value remained unexplored. Here, we realized the entangled antiferromagnetic quantum spin-1/2 Heisenberg model with diazahexabenzocoronene oligomers (up to 7 units) on Au(111). Extensive low-temperature scanning tunneling microscopy/spectroscopy measurements and density functional theory and many-body calculations show that even-numbered spin chains host a collective state with gapped excitations, while odd-numbered chains feature a Kondo excitation. We found that a given antiferromagnetic coupling J value between first neighbors in the entangled quantum states is responsible for the quantum phenomena, strongly relating to their parities of the chain. The tunable molecular building blocks act as an ideal platform for the experimental realization of topological spin lattices.
