文献类型：期刊文献

英文题名：Fractional Spinon Quasiparticles in Open-Shell Triangulene Spin-1/2 Chains

作者：Yuan, Zhangyu[1];Zhang, Xin-Yu[2];Jiang, Yashi[1];Qian, Xiangjian[1];Wang, Ying[2];Liu, Yufeng[1];Liu, Liang[3,4,5];Liu, Xiaoxue[3,4,5];Guan, Dandan[3,4,5];Li, Yaoyi[3,4,5];Zheng, Hao[3,4,5];Liu, Canhua[3,4,5];Jia, Jinfeng[3,4,5];Qin, Mingpu[1,5];Liu, Pei-Nian[2,6];Li, Deng-Yuan[6];Wang, Shiyong[3,4,5]

机构：[1]Shanghai Jiao Tong Univ, TD Lee Inst, Sch Phys & Astron, Key Lab Artificial Struct & Quantum Control,Minist, Shanghai 200240, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China;[3]Shanghai Jiao Tong Univ, Tsung Dao Lee Inst, Shanghai 201210, Peoples R China;[4]Shanghai Jiao Tong Univ, Sch Phys & Astron, Key Lab Artificial Struct & Quantum Control, Minist Educ, Shanghai 200240, Peoples R China;[5]Hefei Natl Lab, Hefei 230088, Peoples R China;[6]China Pharmaceut Univ, Sch Pharm, State Key Lab Nat Med, Nanjing 211198, Peoples R China

年份：2025

卷号：147

期号：6

起止页码：5004

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20250517795901);WOS:【SCI-EXPANDED(收录号:WOS:001408107200001)】；

基金：We thank the Ministry of Science and Technology of China (Grants No. 2020YFA0309000), NSFC (Grants No. 92365302, No. 22325203, No. 92265105, 92065201, No. 12074247, No. 12174252, No. 22272050, No. 21925201), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000), and the Science and Technology Commission of Shanghai Municipality (Grants No. 2019SHZDZX01, No. 19JC1412701, No. 20QA1405100) for financial support. We also thank the financial support from the Innovation Program for Quantum Science and Technology (Grant No. 2021ZD0302500) and the Shanghai Municipal Science and Technology Qi Ming Xing Project (No. 22QA1403000).

语种：英文

外文关键词：Antiferromagnetism - Chain length - Energy dispersive spectroscopy - Molecules - Quantum optics - Scanning probe microscopy - Spin dynamics - Spin waves

摘要：The emergence of spinon quasiparticles, which carry spin but lack charge, is a hallmark of collective quantum phenomena in low-dimensional quantum spin systems. While the existence of spinons has been demonstrated through scattering spectroscopy in ensemble samples, real-space imaging of these quasiparticles within individual spin chains has remained elusive. In this study, we construct individual Heisenberg antiferromagnetic spin-1/2 chains using open-shell [2]triangulene molecules as building blocks. Each [2]triangulene unit, owing to its sublattice imbalance, hosts a net spin-1/2 in accordance with Lieb's theorem, and these spins are antiferromagnetically coupled within covalent chains with a coupling strength of J = 45 meV. Through scanning tunneling microscopy and spectroscopy, we probe the spin states, excitation gaps, and their spatial excitation weights within covalent spin chains of varying lengths with atomic precision. Our investigation reveals that the excitation gap decreases as the chain length increases, extrapolating to zero for long chains, consistent with Haldane's gapless prediction. Moreover, inelastic tunneling spectroscopy reveals an m-shaped energy dispersion characteristic of confined spinon quasiparticles in a one-dimensional quantum box. These findings establish a promising strategy for exploring the unique properties of excitation quasiparticles and their broad implications for quantum information.