Dielectric engineeringin monolayer WSe<sub>2</sub>/graphene heterostructures

Yang Xu; Connor Horn; Daniel A Rhodes; Kenji Watanabe; Takashi Taniguchi; James C Hone; Jie Shan; Kin Fai Mak

Dielectric engineeringin monolayer WSe<sub>2</sub>/graphene heterostructures

ORAL

Abstract

The strong Coulomb interaction between charge carriers in atomically thin transition metal dichalcogenides (e.g. MoS₂, WSe₂) is sensitive to the nearby dielectric environment. Here, we investigate the optical response of monolayer WSe₂, which is in contact with gate-tunable graphene in van der Waals heterostructures, by optical reflection spectroscopy. We find that both the exciton binding energy and quasiparticle bandgap of WSe₂can be renormalized by the dielectric screening effect. The effect can also be modulated upon the formation of Landau levels in graphene under perpendicular magnetic fields. Furthermore, we directly observe inter-band Landau level transitions of WSe₂, which helps to accurately determine the quasiparticle bandgap and effective cyclotron mass in WSe₂ as a function of dielectric screening.

March 4, 2020, 3:51 PM – March 4, 2020, 4:03 PM

Presenters

Yang Xu

Purdue University, Cornell University, NY, USA, Applied and Engineering Physics, Cornell University, Cornell University

Authors

Yang Xu

Purdue University, Cornell University, NY, USA, Applied and Engineering Physics, Cornell University, Cornell University
Connor Horn

Cornell University, NY, USA
Daniel A Rhodes

Columbia University, Columbia Univ, Mechanical Engineering, Columbia University, Columbia University, NY, USA, Department of Mechanical Engineering, Columbia University
Kenji Watanabe

National Institute for Materials Science, Japan, National Institute for Material Science, National Institute for Materials Science, National Institute for Materials Science, Tsukuba, Research Center for Functional Materials, NIMS, nims, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS, National Institute for Material Science - Japan, NIMS Tsukuba, National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute for Materials Science (NIMS), National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan, Advanced Materials Laboratory, NIMS, Japan, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Materials Science, National Institute for Materials Science, University of Tsukuba, National Institute for Materials Science, Tsukuba, Japan, National Institute for Material Science, Japan, National Institue for Material Science, Tsukuba, Advanced Materials Laboratory, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan, Advanced Matrials Lab, NIMS, National Institute for Material Science, Tsukuba, Japan, National institute for materials science, NIMS-Tsukuba, NIMS, Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, NIRM, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Advanced Materials Laboratory, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science (Japan), Physics, NIMS, National Institute of Materials Science, Japan, National Institute of Materials Science (NIMS), National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, NIMS - Tsukuba
Takashi Taniguchi

National Institute for Materials Science, Japan, National Institute for Material Science, National Institute for Materials Science, National Institute for Materials Science, Tsukuba, Research Center for Functional Materials, NIMS, nims, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS, National Institute for Material Science - Japan, NIMS Tsukuba, National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute for Materials Science (NIMS), National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan, Advanced Materials Laboratory, NIMS, Japan, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Materials Science, National Institute for Materials Science, University of Tsukuba, National Institute for Materials Science, Tsukuba, Japan, National Institue for Material Science, Tsukuba, Advanced Materials Laboratory, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan, Advanced Matrials Lab, NIMS, National Institute for Material Science, Tsukuba, Japan, National institute for materials science, NIMS-Tsukuba, NIMS, Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Advanced Materials Laboratory, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science (Japan), Physics, NIMS, National Institute of Materials Science, Japan, National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, NIMS - Tsukuba
James C Hone

Columbia University, Mechanical Engineering, Columbia University, Columbia Univ, Physics, Columbia University, Columbia University, NY, USA, Department of Mechanical Engineering, Columbia University
Jie Shan

Cornell University, School of Applied and Engineering Physics and Department of Physics, Cornell University, Cornell University, NY, USA, Physics, Cornell University, Case Western Reserve University
Kin Fai Mak

Cornell University, School of Applied and Engineering Physics, Cornell University, Cornell University, NY, USA, Applied and Engineering Physics, Cornell University