Tanaka M, Fujishiro Y, Mogi M, Kaneko Y, Yokosawa T, Kanazawa N, Minami S, Koretsune T, Arita R, Tarucha S, Yamamoto M, Tokura Y
Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
Nano Lett. 2020 Oct 14;20(10):7476-7481. doi: 10.1021/acs.nanolett.0c02962. Epub 2020 Sep 15.
Magnetic Weyl semimetals attract considerable interest not only for their topological quantum phenomena but also as an emerging materials class for realizing quantum anomalous Hall effect in the two-dimensional limit. A shandite compound CoSnS with layered kagome-lattices is one such material, where vigorous efforts have been devoted to synthesize the two-dimensional crystal. Here, we report a synthesis of CoSnS thin flakes with a thickness of 250 nm by chemical vapor transport method. We find that this facile bottom-up approach allows the formation of large-sized CoSnS thin flakes of high-quality, where we identify the largest electron mobility (∼2600 cm V s) among magnetic topological semimetals, as well as the large anomalous Hall conductivity (∼1400 Ω cm) and anomalous Hall angle (∼32%) arising from the Berry curvature. Our study provides a viable platform for studying high-quality thin flakes of magnetic Weyl semimetal and stimulate further research on unexplored topological phenomena in the two-dimensional limit.
磁性外尔半金属不仅因其拓扑量子现象而备受关注，而且作为一类新兴材料，有望在二维极限下实现量子反常霍尔效应。具有层状 Kagome 晶格的硫锡钴矿化合物 CoSnS 就是这样一种材料，人们一直在大力致力于合成这种二维晶体。在此，我们报告了通过化学气相传输法合成厚度为 250 nm 的 CoSnS 薄片。我们发现，这种简便的自下而上方法能够形成高质量的大尺寸 CoSnS 薄片，在此我们确定了其在磁性拓扑半金属中具有最大的电子迁移率（约 2600 cm² V⁻¹ s⁻¹），以及由贝里曲率引起的大反常霍尔电导率（约 1400 Ω⁻¹ cm⁻¹）和反常霍尔角（约 32%）。我们的研究为研究高质量的磁性外尔半金属薄片提供了一个可行的平台，并激发了对二维极限下未探索的拓扑现象的进一步研究。
