Chenxiao Zhao, Gonçalo Catarina, Jin-Jiang Zhang, João C. G. Henriques, Lin Yang, Ji Ma, Xinliang Feng, Oliver Gröning, Pascal Ruffieux, Joaquín Fernández-Rossier, Roman Fasel
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引用次数: 0
Abstract
Unlocking the potential of topological order in many-body spin systems has been a key goal in quantum materials research. Despite extensive efforts, the quest for a versatile platform enabling site-selective spin manipulation, essential for tuning and probing diverse topological phases, has persisted. Here we utilize on-surface synthesis to construct spin-1/2 alternating-exchange Heisenberg chains by covalently linking Clar’s goblets—nanographenes each hosting two antiferromagnetically coupled spins. Using scanning tunnelling microscopy, we exert atomic-scale control over chain lengths, parities and exchange-coupling terminations, and probe their magnetic response via inelastic tunnelling spectroscopy. Our investigation confirms the gapped nature of bulk excitations in the chains, known as triplons. Their dispersion relation is extracted from the spatial variation of tunnelling spectral amplitudes. Depending on the parity and termination of chains, we observe varying numbers of in-gap spin-1/2 edge excitations, reflecting the degeneracy of distinct topological ground states in the thermodynamic limit. By monitoring interactions between these edge spins, we identify the exponential decay of spin correlations. Our findings present a phase-controlled many-body platform, opening avenues toward spin-based quantum devices.
期刊介绍:
Nature Nanotechnology is a prestigious journal that publishes high-quality papers in various areas of nanoscience and nanotechnology. The journal focuses on the design, characterization, and production of structures, devices, and systems that manipulate and control materials at atomic, molecular, and macromolecular scales. It encompasses both bottom-up and top-down approaches, as well as their combinations.
Furthermore, Nature Nanotechnology fosters the exchange of ideas among researchers from diverse disciplines such as chemistry, physics, material science, biomedical research, engineering, and more. It promotes collaboration at the forefront of this multidisciplinary field. The journal covers a wide range of topics, from fundamental research in physics, chemistry, and biology, including computational work and simulations, to the development of innovative devices and technologies for various industrial sectors such as information technology, medicine, manufacturing, high-performance materials, energy, and environmental technologies. It includes coverage of organic, inorganic, and hybrid materials.