中国物理B ›› 2021, Vol. 30 ›› Issue (7): 77803-077803.doi: 10.1088/1674-1056/ac051f

所属专题: SPECIAL TOPIC — Twistronics

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Faraday rotations, ellipticity, and circular dichroism in magneto-optical spectrum of moiré superlattices

J A Crosse1,2 and Pilkyung Moon1,2,3,†   

  1. 1 Arts and Sciences, New York University Shanghai, Shanghai 200122, China;
    2 NYU-ECNU Institute of Physics at NYU Shanghai, Shanghai 200062, China;
    3 Department of Physics, New York University, New York 10003, USA
  • 收稿日期:2021-02-19 修回日期:2021-05-21 接受日期:2021-05-26 出版日期:2021-06-22 发布日期:2021-06-26
  • 通讯作者: Pilkyung Moon E-mail:pilkyung.moon@nyu.edu
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12050410228 and 12074260) and the Fund from the Science and Technology Commission of Shanghai Municipality, China (Grant No. 19ZR1436400).

Faraday rotations, ellipticity, and circular dichroism in magneto-optical spectrum of moiré superlattices

J A Crosse1,2 and Pilkyung Moon1,2,3,†   

  1. 1 Arts and Sciences, New York University Shanghai, Shanghai 200122, China;
    2 NYU-ECNU Institute of Physics at NYU Shanghai, Shanghai 200062, China;
    3 Department of Physics, New York University, New York 10003, USA
  • Received:2021-02-19 Revised:2021-05-21 Accepted:2021-05-26 Online:2021-06-22 Published:2021-06-26
  • Contact: Pilkyung Moon E-mail:pilkyung.moon@nyu.edu
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12050410228 and 12074260) and the Fund from the Science and Technology Commission of Shanghai Municipality, China (Grant No. 19ZR1436400).

摘要: We study the magneto-optical conductivity of a number of van der Waals heterostructures, namely, twisted bilayer graphene, AB-AB and AB-BA stacked twisted double bilayer graphene and monolayer graphene and AB-stacked bilayer graphene on hexagonal boron nitride. As the magnetic field increases, the absorption spectrum exhibits a self-similar recursive pattern reflecting the fractal nature of the energy spectrum. Whilst twisted bilayer graphene displays only weak circular dichroism, the other four structures display strong circular dichroism with monolayer graphene and AB-stacked bilayer graphene on hexagonal boron nitride being particularly pronounced owing to strong inversion symmetry breaking properties of the hexagonal boron nitride layer. As the left and right circularly polarized light interact with these structures differently, plane-polarized incident light undergoes a Faraday rotation and gains an ellipticity when transmitted. The size of the respective angles is on the order of a degree.

关键词: 2D-materials, van der Waals heterostructures, magneto-optical conductivity, graphene

Abstract: We study the magneto-optical conductivity of a number of van der Waals heterostructures, namely, twisted bilayer graphene, AB-AB and AB-BA stacked twisted double bilayer graphene and monolayer graphene and AB-stacked bilayer graphene on hexagonal boron nitride. As the magnetic field increases, the absorption spectrum exhibits a self-similar recursive pattern reflecting the fractal nature of the energy spectrum. Whilst twisted bilayer graphene displays only weak circular dichroism, the other four structures display strong circular dichroism with monolayer graphene and AB-stacked bilayer graphene on hexagonal boron nitride being particularly pronounced owing to strong inversion symmetry breaking properties of the hexagonal boron nitride layer. As the left and right circularly polarized light interact with these structures differently, plane-polarized incident light undergoes a Faraday rotation and gains an ellipticity when transmitted. The size of the respective angles is on the order of a degree.

Key words: 2D-materials, van der Waals heterostructures, magneto-optical conductivity, graphene

中图分类号:  (Multilayers; superlattices; photonic structures; metamaterials)

  • 78.67.Pt
78.20.Ls (Magneto-optical effects) 78.67.Wj (Optical properties of graphene) 78.20.Bh (Theory, models, and numerical simulation)