Wong Chi Ho, Guo Zongliang, Lam King Cheong, Chau Chun Pong, Chan Wing Yu, Tang Chak-Yin, Tsang Yuen Hong, Lam Leung Yuk Frank, Hu Xijun
Division of Science, Engineering and Health Studies, School of Professional Education and Executive Development, The Hong Kong Polytechnic University, Hong Kong, China.
Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China.
Mater Horiz. 2025 Jul 17. doi: 10.1039/d5mh00664c.
The emergence of exotic charge density waves (CDW) alongside ferrimagnetic materials opens exciting new possibilities for quantum switching, particularly in field-tuning CDW electronics. However, these two phenomena often compete and rely heavily on strong electronic correlations. While carbon nanowire arrays have been experimentally shown to exhibit ferromagnetism above 400 K, our research shows that encapsulating a linear carbon chain (LCC) within zigzag boron nitride nanotubes (BNT) induces a short-range CDW state under the competing effect of ferrimagnetism and magnetic frustrations. However, for this exotic phenomenon to occur, the LCC needs to break the symmetry along the circular plane of the BNT. Then we utilize a Monte Carlo model to identify the cut-off length of LCC@BNT to tackle its size effect, while also comparing the stability of chains provided by carbon nanotubes. The shorter LCC@BNT displays a more prominent long-range CDW pattern with a tunneling barrier of 2.3 eV on the Fermi surface, transitioning into an insulator. Meanwhile, magnetic frustrations disappear, and ferrimagnetism remains stable up to 280 K. Our discovery of ferrimagnetic CDW carbyne insulators, which function without conventional periodic lattice distortion, spin-orbit coupling, heavy elements, or complex d and f hybridization represents a groundbreaking shift in thinking, which demonstrates that such exotic properties are not exclusive to transition metal elements.
外来电荷密度波（CDW）与亚铁磁性材料的出现为量子开关带来了令人兴奋的新可能性，特别是在场调谐CDW电子学方面。然而，这两种现象常常相互竞争，并且严重依赖于强电子关联。虽然实验表明碳纳米线阵列在400 K以上表现出铁磁性，但我们的研究表明，将线性碳链（LCC）封装在锯齿形氮化硼纳米管（BNT）内会在亚铁磁性和磁阻挫的竞争作用下诱导出短程CDW状态。然而，要出现这种奇异现象，LCC需要打破沿BNT圆形平面的对称性。然后我们利用蒙特卡罗模型来确定LCC@BNT的截止长度以解决其尺寸效应，同时还比较了碳纳米管提供的链的稳定性。较短的LCC@BNT显示出更显著的长程CDW模式，在费米面上具有2.3 eV的隧穿势垒，转变为绝缘体。与此同时，磁阻挫消失，亚铁磁性在高达280 K时保持稳定。我们发现的亚铁磁性CDW卡宾绝缘体，其功能无需传统的周期性晶格畸变、自旋轨道耦合、重元素或复杂的d和f杂化，这代表了思维上的突破性转变，表明这种奇异特性并非过渡金属元素所独有。
