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Public Seminar of RPg Student:
Manipulation and Utilization of Optical Polarization of the Moire Exciton


Speaker:Mr. Huiyuan ZHENG
Affiliation:The University of Hong Kong
Date:June 11, 2020 (Thursday)
Time:12:00 n.n.
Venue:Room 522, 5/F, Chong Yuet Ming Physics Building, HKU
ZOOM ID: 979 5292 6429

Abstract
 

The interlayer exciton in the moire lattice of the heterobilayer transition metal dichalcogenides (TMDs) has grasped scientists’ attention in recent years. Due to the valley mismatch, the interlayer exciton possesses the anomalous light cones located at finite velocities on the parabolic energy dispersion. Besides, the local variation of the layer coupling induces the moire potential on the interlayer excitons, which couples the different light cones, displaying the novel optical properties. We apply the uniaxial strain onto the bilayer TMDs to investigate the effect of the gauge field to the anomalous light cones. In the presence of the strain, apart from the deformation of the Brillouin zone, energy valleys are further shifted, causing the light cones to display the novel degeneracy. In addition, the position-dependent polarization property of the interlayer exciton could be utilized. By placing the heterobilayer TMDs on the photonic crystal, the exciton polarization is correlated to the wavevector of the emitted light, so that we can realize the position-wavevector locking of the light.

Anyone interested is welcome to attend.