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Intrinsic valley Hall transport in atomically thin MoS(2)

Electrons hopping in two-dimensional honeycomb lattices possess a valley degree of freedom in addition to charge and spin. In the absence of inversion symmetry, these systems were predicted to exhibit opposite Hall effects for electrons from different valleys. Such valley Hall effects have been achi...

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Detalles Bibliográficos
Autores principales: Wu, Zefei, Zhou, Benjamin T., Cai, Xiangbin, Cheung, Patrick, Liu, Gui-Bin, Huang, Meizhen, Lin, Jiangxiazi, Han, Tianyi, An, Liheng, Wang, Yuanwei, Xu, Shuigang, Long, Gen, Cheng, Chun, Law, Kam Tuen, Zhang, Fan, Wang, Ning
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6363770/
https://www.ncbi.nlm.nih.gov/pubmed/30723283
http://dx.doi.org/10.1038/s41467-019-08629-9
Descripción
Sumario:Electrons hopping in two-dimensional honeycomb lattices possess a valley degree of freedom in addition to charge and spin. In the absence of inversion symmetry, these systems were predicted to exhibit opposite Hall effects for electrons from different valleys. Such valley Hall effects have been achieved only by extrinsic means, such as substrate coupling, dual gating, and light illuminating. Here we report the first observation of intrinsic valley Hall transport without any extrinsic symmetry breaking in the non-centrosymmetric monolayer and trilayer MoS(2), evidenced by considerable nonlocal resistance that scales cubically with local resistance. Such a hallmark survives even at room temperature with a valley diffusion length at micron scale. By contrast, no valley Hall signal is observed in the centrosymmetric bilayer MoS(2). Our work elucidates the topological origin of valley Hall effects and marks a significant step towards the purely electrical control of valley degree of freedom in topological valleytronics.