UCR主導の研究で報告された技術は、ナノエレクトロニクスへの応用が可能。 Technology reported in UC Riverside-led study has nanoelectronic applications
2022-09-04 カリフォルニア大学リバーサイド校(UCR)
単層WTe2を、数原子層厚の絶縁性強磁性体-Cr2Ge2Te6、または単にCGT-と積層し、WTe2が、導電性エッジを持つ強磁性を発現したことを発見した。
電子のエッジフローは一方向であり、外部磁場を用いて方向を切り替えることができる。
Shiは、エッジだけが電気を通す時、材料内部のサイズは取るに足らないので、そのような材料を使った電子デバイスは、より小さく、実際、導電エッジとほぼ同じ大きさにすることが出来る
＜関連情報＞
- https://news.ucr.edu/articles/2022/09/06/researchers-devise-tunable-conducting-edge
- https://www.nature.com/articles/s41467-022-32808-w
近接磁化量子スピンホール絶縁体：単層1 T’ WTe2/Cr2Ge2Te6 Proximity-magnetized quantum spin Hall insulator: monolayer 1 T’ WTe2/Cr2Ge2Te6
Junxue Li,Mina Rashetnia,Mark Lohmann,Jahyun Koo,Youming Xu,Xiao Zhang,Kenji Watanabe,Takashi Taniguchi,Shuang Jia,Xi Chen,Binghai Yan,Yong-Tao Cui & Jing Shi
Nature Communications Published:01 September 2022
DOI:https://doi.org/10.1038/s41467-022-32808-w
Abstract
Van der Waals heterostructures offer great versatility to tailor unique interactions at the atomically flat interfaces between dissimilar layered materials and induce novel physical phenomena. By bringing monolayer 1 T’ WTe2, a two-dimensional quantum spin Hall insulator, and few-layer Cr2Ge2Te6, an insulating ferromagnet, into close proximity in an heterostructure, we introduce a ferromagnetic order in the former via the interfacial exchange interaction. The ferromagnetism in WTe2 manifests in the anomalous Nernst effect, anomalous Hall effect as well as anisotropic magnetoresistance effect. Using local electrodes, we identify separate transport contributions from the metallic edge and insulating bulk. When driven by an AC current, the second harmonic voltage responses closely resemble the anomalous Nernst responses to AC temperature gradient generated by nonlocal heater, which appear as nonreciprocal signals with respect to the induced magnetization orientation. Our results from different electrodes reveal spin-polarized edge states in the magnetized quantum spin Hall insulator.
