Optical control of the layer degree of freedom through Wannier–Stark states in polar 3R MoS2. (23rd May 2019)

• Record Type: Journal Article
• Authors: Park, Jaehong; Yeu, In Won; Han, Gyuseung; Jang, Chaun; Kwak, Joon Young; Hwang, Cheol Seong; Choi, Jung-Hae
• Is Part Of: Journal of physics. Volume 31:Number 31(2019)
• Publication Date: 2019-05-23
• Subjects: polar symmetry 3R MoS2 -- layer-index -- optical selection rule -- transition metal dichalcogenide; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ab1d0f
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Electrons in two-dimensional layered crystals gain a discrete positional degree of freedom over layers. We propose the two-dimensional transition metal dichalcogenide homostructure with polar symmetry as a prototypical platform where the degrees of freedom for the layers and valleys can be independently controlled through an optical method. In 3R MoS2, a model system, the presence of the spontaneous polarization and built-in electric field along the stacking axis is theoretically proven by the density functional theory. The K valley states under the electric field exhibit Wannier–Stark type localization with atomic-scale confinement driven by double group symmetry. The simple interlayer-dynamics-selection rule of the valley carriers in 3R homostructure enables a binary operation, upward or downward motion, using visible and infrared light sources. Together with the valley-index, a 2 2 states/cell device using a dual-frequency polarized light source is suggested.