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 bil...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 bilayerα-MoO_(3).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 bilayerα-MoO_(3)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 twoα-MoO_(3)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 bilayerα-MoO_(3),but also looks forward to applications in biolo gical sensing.展开更多
基金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)+4 种基金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.GXYD 14.26)the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2020LLZ004)the Start-Up Funding of Guangdong Polytechnic Normal University,China(Gtrant No.2021SDKYA033)。
文摘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 bilayerα-MoO_(3).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 bilayerα-MoO_(3)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 twoα-MoO_(3)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 bilayerα-MoO_(3),but also looks forward to applications in biolo gical sensing.
