英国剑桥大学Raj Pandya团队研究了磷烯纳米带中的磁性和光学活性边缘。该项研究成果发表在2025年3月12日出版的《自然》杂志上。

纳米带，即二维材料的纳米宽条带，是凝聚态物质中一个独特的系统。它们将低维材料的奇异电子结构与更多的暴露边缘相结合，在这些边缘处可以出现超长自旋相干时间、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半导体电子结构和磁性的潜力，这是基于自旋的电子器件（如（低能）非易失性晶体管）的关键特性。

研究组报告了磷烯纳米带（PNR）的磁性和半导体性能。并证明在室温下，PNR薄膜显示出由其边缘产生的宏观磁性，内部场约为240至850 mT。在溶液中，巨大的磁各向异性使PNR能够在亚1-T场下排列。通过利用这种排列效应，研究组发现在光激发下，能量会迅速汇集到一个位于磁边缘并与对称禁边声子模式耦合的状态。该研究结果将PNR确立为研究室温下磁性和半导体基态之间相互作用的吸引人的系统，并为在量子电子学中使用低维纳米材料奠定了基础。

附：英文原文

Title: Magnetically and optically active edges in phosphorene nanoribbons

Author: 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

Issue&Volume: 2025-03-12

Abstract: 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 times1,2, quantum confinement3 and topologically protected states4,5 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 transistors6. 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 850mT. 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.

DOI: 10.1038/s41586-024-08563-x

Source: https://www.nature.com/articles/s41586-024-08563-x