Exciton Hall effect in monolayer MoS2
Exciton Hall effect in monolayer MoS2
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DOI：
10.1038/nmat4996
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发表时间：
2017-12-01
期刊：
影响因子：
41.2
通讯作者：
Iwasa, Yoshihiro
中科院分区：
文献类型：
--
作者：
Onga, Masaru;Zhang, Yijin;Iwasa, Yoshihiro
量子Berry相(动量空间中的内部磁通)驱动的自发霍尔效应体现了准粒子的拓扑性质，可以用来控制信息流，如自旋和谷值(1，2)。我们报道了激子的霍尔效应(半导体中主导光学响应的电子和空穴的基本复合粒子(3))。通过偏振分辨光致发光作图，我们直接观察到了单层MoS_2中激子的霍尔效应和微米尺度上激子的谷选择性空间输运。在单层MoS_2中，激子的霍尔角比单电子的霍尔角大得多。4)，表明复合粒子的量子输运明显受其内部结构的影响。这一结果不仅提出了复合粒子中霍尔效应的一个基本问题，而且为探索二维材料中激子基谷电子学提供了一条途径。
The spontaneous Hall effect driven by the quantum Berry phase (which serves as an internal magnetic flux in momentum space) manifests the topological nature of quasiparticles and can be used to control the information flow, such as spin and valley(1,2). We report a Hall effect of excitons (fundamental composite particles of electrons and holes that dominate optical responses in semiconductors(3)). By polarization-resolved photoluminescence mapping, we directly observed the Hall effect of excitons in monolayer MoS2 and valley-selective spatial transport of excitons on a micrometre scale. The Hall angle of excitons is found to be much larger than that of single electrons in monolayer MoS2 (ref. 4), implying that the quantum transport of the composite particles is significantly affectedby their internal structures. Thepresent result not only poses a fundamental problem of the Hall effect in composite particles, but also offers a route to explore exciton-based valleytronics in two-dimensional materials.