Van der Waals engineering of ferromagnetic semiconductor heterostructures for spin and valleytronics.
Van der Waals engineering of ferromagnetic semiconductor heterostructures for spin and valleytronics.
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DOI：
10.1126/sciadv.1603113
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发表时间：
2017-05
期刊：
影响因子：
13.6
通讯作者：
Xu X
中科院分区：
文献类型：
--
作者：
Zhong D;Seyler KL;Linpeng X;Cheng R;Sivadas N;Huang B;Schmidgall E;Taniguchi T;Watanabe K;McGuire MA;Yao W;Xiao D;Fu KC;Xu X
单层 WSe2 和铁磁 CrI3 的范德华异质结构能够对谷赝自旋进行出色的控制。磁性材料与半导体的集成为基础科学奠定了沃土，并且对信息处理和存储的无缝集成具有巨大的实际意义。我们创建了由超薄铁磁半导体 CrI3 和单层 WSe2 形成的范德华异质结构。我们观察到 WSe2 中自旋和谷赝自旋的前所未有的控制，其中我们检测到近 13 T 的大磁交换场，并通过 CrI3 磁化强度的翻转来快速切换 WSe2 谷分裂和极化。 WSe2 光致发光强度很大程度上取决于 WSe2 中光激发自旋与 CrI3 磁化强度之间的相对排列，因为跨异质结构界面的超快自旋相关电荷跳跃。谷赝自旋的光致发光检测提供了一种简单而灵敏的方法来探测超薄磁体中有趣的磁域动力学，以及异质结构内丰富的自旋相互作用。
A van der Waals heterostructure of monolayer WSe2 and ferromagnetic CrI3 enables exceptional control of valley pseudospin. The integration of magnetic material with semiconductors has been fertile ground for fundamental science as well as of great practical interest toward the seamless integration of information processing and storage. We create van der Waals heterostructures formed by an ultrathin ferromagnetic semiconductor CrI3 and a monolayer of WSe2. We observe unprecedented control of the spin and valley pseudospin in WSe2, where we detect a large magnetic exchange field of nearly 13 T and rapid switching of the WSe2 valley splitting and polarization via flipping of the CrI3 magnetization. The WSe2 photoluminescence intensity strongly depends on the relative alignment between photoexcited spins in WSe2 and the CrI3 magnetization, because of ultrafast spin-dependent charge hopping across the heterostructure interface. The photoluminescence detection of valley pseudospin provides a simple and sensitive method to probe the intriguing domain dynamics in the ultrathin magnet, as well as the rich spin interactions within the heterostructure.