Stacking Induced Spontaneous Polarization in Rhombohedral MoS2

          @misc{ pirsa_PIRSA:22110064,
            doi = {10.48660/22110064},
            url = {https://pirsa.org/22110064},
            author = {Ye, Ziliang},
            keywords = {Condensed Matter},
            language = {en},
            title = {Stacking Induced Spontaneous Polarization in Rhombohedral MoS2},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {nov},
            note = {PIRSA:22110064 see, \url{https://pirsa.org}}
          }
          

Abstract

"The relatively weak van der Waals bond in 2D materials has ushered in a rich new era of stacking engineering. We recently found in rhombohedrally stacked MoS2, a Berry phase contrast between layers can induce an asymmetric interlayer coupling and an out-of-plane spontaneous electrical polarization (1). The polarization direction can be switched via interlayer sliding, forming a new type of ferroelectricity. In addition, we demonstrated that such a polarization can lead to a spontaneous photovoltaic effect without any pn junctions (2). Compared to conventional PV effects, our device shows a similar quantum efficiency with an ultrafast speed and potentially a programmable polarity. The rhombohedrally stacked transition metal dichalcogenides therefore provide a new platform for studying spontaneous polarization at the atomic scale. (1) Jing Liang, et al, arXiv:2209.06966 (2022). (2) Dongyang Yang, et al, Nature Photonics, 16, 469–474 (2022)."