文献类型：期刊文献

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

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

机构：[1] Key Laboratory of Artificial Structures and Quantum Control [Ministry of Education], TD Lee Institute, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China; [2] Key Laboratory of Natural Medicines, Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, 211198, China; [3] Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, State Key Laboratory of Chemical Engineering, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China; [4] Hefei National Laboratory, Hefei, 230088, China

年份：2024

外文期刊名：arXiv

收录：EI(收录号：20240357397)

语种：英文

外文关键词：Antiferromagnetism - Atoms - Chain length - Energy dispersive spectroscopy - Energy gap - Excited states - Molecules - Quantum interference phenomena - Quantum optics - Scanning probe microscopy - Spin dynamics

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. Copyright ? 2024, The Authors. All rights reserved.