[23p-B203-1~13] 17.3 Layered materials

△ [23p-B203-12] Laser ARPES and second harmonic generation in twisted bilayer WTe₂

〇Keisuke Kamiya¹, Yijin Zhang¹, Takato Yamamoto², Masato Sakano², Keisuke Shinokita³, Shota Okazaki⁴, Satoru Masubuchi¹, Kenji Watanabe⁵, Takashi Taniguchi^1,5, Takao Sasagawa⁴, Kazunari Matsuda³, Kyoko Ishizaka^2,6, Tomoki Machida^1,7 (1.IIS, Univ. of Tokyo, 2.Univ. of Tokyo, 3.IAE, Kyoto Univ., 4.MSL, Tokyo Tech, 5.NIMS, 6.CEMS, RIKEN, 7.CREST-JST)

Keywords:transition metal dichalcogenide, symmetry, twisted van der Waals heterostructure

In the natural structure of the layered material WTe₂, layers are stacked with the rotation of 180 degree. Therefore, the number of layers determines the symmetry and the appearance of many interesting properties. The twisted van der Waals heterostructure is a unique technique that can control the symmetry of the layer materials. In this study, we fabricated the 0 degree-twisted bilayer WTe₂ to study the influence of the symmetry upon physical properties. We used the laser angle-resolved photoemission spectroscopy to directly observe the band dispersion. The symmetry of the bilayer WTe₂ was further analyzed by the output of the optical second harmonic generation. We found that the twist angle strongly modulate the symmetry and the physical properties of the bilayer WTe₂.