中国物理B ›› 2022, Vol. 31 ›› Issue (4): 44101-044101.doi: 10.1088/1674-1056/ac3740

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Strong chirality in twisted bilayer α-MoO3

Bi-Yuan Wu(吴必园)1,2, Zhang-Xing Shi(石章兴)2, Feng Wu(吴丰)3, Ming-Jun Wang(王明军)1,4,†, and Xiao-Hu Wu(吴小虎)2,‡   

  1. 1 School of Automation and Information Engineering, Xi'an University of Technology, Xi'an 710048, China;
    2 Shandong Institute of Advanced Technology, Jinan 250100, China;
    3 School of Optoelectronic Engineering, Guangdong Polytechnic Normal University, Guangzhou 510665, China;
    4 School of Physics and Telecommunications Engineering, Shaanxi University of Technology, Hanzhong 723001, China
  • 收稿日期:2021-09-26 修回日期:2021-10-22 接受日期:2021-11-06 出版日期:2022-03-16 发布日期:2022-03-25
  • 通讯作者: Ming-Jun Wang, Xiao-Hu Wu E-mail:wangmingjun@xaut.edu.cn;xiaohu.wu@iat.cn
  • 基金资助:
    Project supported by the Training Program of the Major Research Plan of the National Natural Science Foundation of China (Grant No. 92052106), the National Natural Science Foundation of China (Grant Nos. 61771385 and 52106099), the Science Foundation for Distinguished Young Scholars of Shaanxi Province, China (Grant No. 2020JC-42), the Science and Technology on Solid-State Laser Laboratory, China (Grant No. 6142404190301), the Science and Technology Research Plan of Xi'an City, China (Grant No. GXYD14.26), the Shandong Provincial Natural Science Foundation, China (Grant No. ZR2020LLZ004), and the Start-Up Funding of Guangdong Polytechnic Normal University, China (Gtrant No. 2021SDKYA033).

Strong chirality in twisted bilayer α-MoO3

Bi-Yuan Wu(吴必园)1,2, Zhang-Xing Shi(石章兴)2, Feng Wu(吴丰)3, Ming-Jun Wang(王明军)1,4,†, and Xiao-Hu Wu(吴小虎)2,‡   

  1. 1 School of Automation and Information Engineering, Xi'an University of Technology, Xi'an 710048, China;
    2 Shandong Institute of Advanced Technology, Jinan 250100, China;
    3 School of Optoelectronic Engineering, Guangdong Polytechnic Normal University, Guangzhou 510665, China;
    4 School of Physics and Telecommunications Engineering, Shaanxi University of Technology, Hanzhong 723001, China
  • Received:2021-09-26 Revised:2021-10-22 Accepted:2021-11-06 Online:2022-03-16 Published:2022-03-25
  • Contact: Ming-Jun Wang, Xiao-Hu Wu E-mail:wangmingjun@xaut.edu.cn;xiaohu.wu@iat.cn
  • Supported by:
    Project supported by the Training Program of the Major Research Plan of the National Natural Science Foundation of China (Grant No. 92052106), the National Natural Science Foundation of China (Grant Nos. 61771385 and 52106099), the Science Foundation for Distinguished Young Scholars of Shaanxi Province, China (Grant No. 2020JC-42), the Science and Technology on Solid-State Laser Laboratory, China (Grant No. 6142404190301), the Science and Technology Research Plan of Xi'an City, China (Grant No. GXYD14.26), the Shandong Provincial Natural Science Foundation, China (Grant No. ZR2020LLZ004), and the Start-Up Funding of Guangdong Polytechnic Normal University, China (Gtrant No. 2021SDKYA033).

摘要: Chiral structures are promising in many applications, such as biological sensing and analytical chemistry, and have been extensively explored. In this paper, we theoretically investigate the chiral response of twisted bilayer α-MoO3. Firstly, the analytical formula for the transmissivity is derived when the structure is illuminated with circularly polarized plane waves. Furthermore, the results demonstrate that the twisted bilayer α-MoO3 can excite the strong chirality with the maximum circular dichroism (CD) of 0.89. In this case, the chirality is due to the simultaneous breaking the rotational symmetry and mirror symmetry, which originates from the relative rotation of two α-MoO3 layers. To better understand the physical mechanism, the polarization conversion between the left-hand circular polarization (LCP) and right-hand circular polarization (RCP) waves is discussed as well. Moreover, it is found that the structure can maintain the strong chirality (CD> 0.8) when the twisted angle varies from 69° to 80°, which effectively reduces the strictness in the requirement for rotation angle. In addition, the CD can be larger than 0.85 when the incidence angle of circularly polarized plane wave is less than 40°, implying that the chirality is robust against the angle of incidence. Our work not only provides an insight into chirality induced by the twisted bilayer α-MoO3, but also looks forward to applications in biological sensing.

关键词: chirality, twisted bilayer, α-MoO3

Abstract: Chiral structures are promising in many applications, such as biological sensing and analytical chemistry, and have been extensively explored. In this paper, we theoretically investigate the chiral response of twisted bilayer α-MoO3. Firstly, the analytical formula for the transmissivity is derived when the structure is illuminated with circularly polarized plane waves. Furthermore, the results demonstrate that the twisted bilayer α-MoO3 can excite the strong chirality with the maximum circular dichroism (CD) of 0.89. In this case, the chirality is due to the simultaneous breaking the rotational symmetry and mirror symmetry, which originates from the relative rotation of two α-MoO3 layers. To better understand the physical mechanism, the polarization conversion between the left-hand circular polarization (LCP) and right-hand circular polarization (RCP) waves is discussed as well. Moreover, it is found that the structure can maintain the strong chirality (CD> 0.8) when the twisted angle varies from 69° to 80°, which effectively reduces the strictness in the requirement for rotation angle. In addition, the CD can be larger than 0.85 when the incidence angle of circularly polarized plane wave is less than 40°, implying that the chirality is robust against the angle of incidence. Our work not only provides an insight into chirality induced by the twisted bilayer α-MoO3, but also looks forward to applications in biological sensing.

Key words: chirality, twisted bilayer, α-MoO3

中图分类号:  (Electromagnetic wave propagation; radiowave propagation)

  • 41.20.Jb
11.30.Rd (Chiral symmetries)