基于狄拉克半金属纳米线的太赫兹可调七波段完美吸收器的模拟仿真  

Simulation of terahertz tunable seven-band perfect absorber based on high frequency detection function of Dirac semi-metallic nanowires

作　　者：卢文强 易颖婷 宋前举 周自刚[1] 易有根[2] 曾庆栋 易早 LU Wenqiang;YI Yingting;SONG Qianju;ZHOU Zigang;YI Yougen;ZENG Qingdong;YI Zao(School of Mathematics and Science,Southwest University of Science and Technology,Mianyang 621010,China;College of Physics,Central South University,Changsha 410083,China;School of Physics and Electronic-information Engineering,Hubei Engineering University,Xiaogan 432000,China;School of Chemistry and Chemical Engineering,Jishou University,Jishou 416000,China)

机构地区：[1]西南科技大学数理学院,绵阳621010 [2]中南大学物理学院,长沙410083 [3]湖北工程学院物理与电子信息工程学院,孝感432000 [4]吉首大学化学化工学院,吉首416000

出　　处：《物理学报》2025年第3期108-117,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12204388,12074151);四川省科学技术厅科研基金(批准号:2022NSFSC1804)资助的课题。

摘　　要：设计了一种高灵敏度、高品质因子、高品质因数、高频探测、双固定功能的太赫兹可调完美吸收器.该吸收器可实现4—14.5 THz范围内7个波段的完美吸收.在进行结构设计时将线阵结构的参数与周期进行了关联.通过计算吸收器的相对阻抗来对器件宏观层面的电磁进行解释,并通过分析共振频率点的表面电场和磁场分布,来分析该器件的物理机制.计算了7个共振频点的品质因子Q,其中最大Q值为219.41.通过改变外部折射率,该吸收器的灵敏度和品质因数值最大可达5421.43 GHz/RIU和35.204 RIU-1.通过讨论关键参数对器件的影响,得出该器件可实现双固定性能的选择、七波段吸收以及全波段反射.通过改变狄拉克半金属的费米能级,证明该吸收器具有良好的动态调节能力.通过改变外部电磁波的入射角发现该器件在中低频段具有良好的稳定性,但在高频段受外部入射角影响较大.本文所提出的吸收器在成像、探测、检测等领域具有巨大的应用潜力,相关工作对光电器件的设计提供了思路.In this work,a tunable perfect absorber in the terahertz range is designed based on Dirac semimetal nanowires,featuring high sensitivity,quality factor,and dual functionality.The absorber achieves perfect absorptions across seven bands in a range of 0–14.5 THz:f_(1)=5.032 THz(84.43%),f_(2)=5.859 THz(96.23%),f_(3)=7.674 THz(91.36%),f_(4)=9.654 THz(99.02%),f_(5)=11.656 THz(93.84%),f_(6)=12.514 THz(98.47%),and f_(7)=14.01 THz(97.32%).To ensure structural stability during design,the periodicity of the wire array structure is carefully considered.Verification of the absorber’s performance is conducted through the calculation of impedance matching.The analyses of the surface electric field and magnetic field at resonance frequency elucidate the underlying physical mechanisms governing the absorber’s characteristics.The values of quality factor(Q)for the seven resonance points are computed,with a maximum Q of 219.41.Further investigations by changing the external refractive index show that the maximum sensitivity value and the figure of merit(FOM)value are 5421.43 GHz/RIU and 35.204 RIU–1,respectively.Then,by discussing the influence of key parameters on the device,we conclude that the device can achieve the choice of dual fixed performance.Dynamic modulation capabilities are demonstrated by changing the Dirac semimetal’s Fermi energy.Additionally,by changing the incident angle of the external electromagnetic wave,it is found that the device has good stability in the medium frequency band and low frequency band,but it is greatly affected by the external incident angle in the high frequency band,thus necessitating careful consideration in practical applications.In conclusion,the proposed absorber holds significant promise for imaging,sensing,and detection applications,providing the valuable insights for designing optoelectronic devices.

关 键 词：超材料 太赫兹 狄拉克半金属 电磁多频吸收 Fano谐振 可调 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O441.4[理学—电磁学]