2020/01/09 by Hui-Ying Mu, Yitong Yao, Yi-Tong Yao +13 · 6 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Brillouin zone #Chemistry #Condensed matter physics #Ferromagnetism #Heterojunction #Materials science #Monolayer #Nanotechnology #Optics #Perovskite Materials and Applications #Physics #Polarization (electrochemistry) #Scattering #Superlattice #Transition Metal Oxide Nanomaterials #Valleytronics #cond-mat.mes-hall
paper · pdf · doi:10.1021/acs.jpclett.0c00863
published in The Journal of Physical Chemistry Letters 11(10), 3882-3888 (American Chemical Society) · 14 pages, 4 figures
arxiv created 2020/01/09 · openalex publication_date 2020/04/27 · arxiv updated 2020/07/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A significant, fundamental challenge in the field of valleytronics is how to generate and regulate valley-polarized currents in practical ways. Here, we discover a new mechanism for producing valley polarization in a monolayer transition metal dichalcogenide superlattice, in which valley-resolved gaps are formed at the supercell Brillouin zone boundaries and centers due to intervalley scattering. When the incident energy of the electron lies in the gaps, the available states are valley polarized, thus providing a valley-polarized current from the superlattice. We show that the direction and strength of the valley polarization may be further tuned by varying the potential applied to the superlattice. The transmission can have a net valley polarization of 55% for a four-period heterostructure. Moreover, two such valley filters in series may function as an electrostatically controlled giant valleyresistance device, representing a zero-magnetic field counterpart to the familiar giant magnetoresistance device.