Ashoka Arjun, Clancy Adam J, Panjwani Naitik A, Cronin Adam, Picco Loren, Aw Eva S Y, Popiel Nicholas J M, Eaton Alexander G, Parton Thomas G, Shutt Rebecca R C, Feldmann Sascha, Carey Remington, Macdonald Thomas J, Liu Cheng, Severijnen Marion E, Kleuskens Sandra, Muscarella Loreta A, Fischer Felix R, Barbosa de Aguiar Hilton, Friend Richard H, Behrends Jan, Christianen Peter C M, Howard Christopher A, Pandya Raj
Cavendish Laboratory, University of Cambridge, Cambridge, UK.
Department of Chemistry, University College London, London, UK.
Nature. 2025 Mar;639(8054):348-353. doi: 10.1038/s41586-024-08563-x. Epub 2025 Mar 12.
Nanoribbons, nanometre-wide strips of a two-dimensional material, are a unique system in condensed matter. They combine the exotic electronic structures of low-dimensional materials with an enhanced number of exposed edges, where phenomena including ultralong spin coherence times, quantum confinement and topologically protected states can emerge. An exciting prospect for this material concept is the potential for both a tunable semiconducting electronic structure and magnetism along the nanoribbon edge, a key property for spin-based electronics such as (low-energy) non-volatile transistors. Here we report the magnetic and semiconducting properties of phosphorene nanoribbons (PNRs). We demonstrate that at room temperature, films of PNRs show macroscopic magnetic properties arising from their edge, with internal fields of roughly 240 to 850 mT. In solution, a giant magnetic anisotropy enables the alignment of PNRs at sub-1-T fields. By leveraging this alignment effect, we discover that on photoexcitation, energy is rapidly funnelled to a state that is localized to the magnetic edge and coupled to a symmetry-forbidden edge phonon mode. Our results establish PNRs as a fascinating system for studying the interplay between magnetism and semiconducting ground states at room temperature and provide a stepping-stone towards using low-dimensional nanomaterials in quantum electronics.
纳米带是二维材料的纳米级宽度条带，是凝聚态物质中的一个独特体系。它们将低维材料奇异的电子结构与数量增加的暴露边缘相结合，在这些边缘可能出现包括超长自旋相干时间、量子限制和拓扑保护态等现象。这种材料概念的一个令人兴奋的前景是，沿着纳米带边缘具有可调谐的半导体电子结构和磁性的潜力，这是诸如（低能量）非易失性晶体管等自旋电子学的关键特性。在此，我们报告了磷烯纳米带（PNR）的磁性和半导体特性。我们证明，在室温下，PNR薄膜因其边缘而呈现宏观磁性，内部磁场约为240至850 mT。在溶液中，巨大的磁各向异性使PNR在低于1 T的磁场下排列。通过利用这种排列效应，我们发现光激发时，能量会迅速汇聚到一个局域于磁性边缘并与对称禁戒边缘声子模式耦合的状态。我们的结果确立了PNR作为一个在室温下研究磁性与半导体基态之间相互作用的迷人体系，并为在量子电子学中使用低维纳米材料提供了一块垫脚石。
