{"title":"利用太赫兹等离子体元表面实现特异点附近的薄膜传感","authors":"I. K. N., Dibakar Roy Chowdhury","doi":"10.1088/1367-2630/ad3fe0","DOIUrl":null,"url":null,"abstract":"\n Non-Hermitian quantum systems along with engineered metasurfaces enable a versatile podium for sensor designs from industrial to medical sectors. The singularity points known as Exceptional points (EP) can be realized in such non-Hermitian systems. EP demonstrates a square root topology on minute perturbations, hence promising to be a potential candidate to sense external parameters, such as temperature, thermal fluctuations, refractive index, and biomolecules. Hence, in this work, through numerical and analytical investigations, we explore the sensing capabilities in the vicinity of EP utilizing suitably designed terahertz metasurfaces. Here, we propose a non-Hermitian metasystem comprising two orthogonally twisted square split ring resonators coupled by near-field EM (Electromagnetic) interactions that can exhibit dark-bright modes. In such a system, the presence of an active (photo-doped) material in the split gap of one of the resonators opens up an effective avenue to introduce controllable asymmetric losses, ultimately leading to the emergence of exceptional points in the polarization space. Hence, thin film sensing at the proximity of the emerged exceptional point is investigated for different refractive indices by coating with an overlayer atop the metasurface. In such a configuration, the sensitivities of the eigenstates are calculated in terms of the Refractive Index Unit, which turns out to be - 0.044 THz/RIU and - 0.063 THz/RIU when the system is perturbed near EP. Our proposed metasurface-inspired EP-based sensing strategy can open up novel ways to sense the refractive index of unknown materials besides other physical parameters.","PeriodicalId":508829,"journal":{"name":"New Journal of Physics","volume":" 5","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Thin Film Sensing near Exceptional Point utilizing Terahertz Plasmonic Metasurfaces\",\"authors\":\"I. K. N., Dibakar Roy Chowdhury\",\"doi\":\"10.1088/1367-2630/ad3fe0\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n Non-Hermitian quantum systems along with engineered metasurfaces enable a versatile podium for sensor designs from industrial to medical sectors. The singularity points known as Exceptional points (EP) can be realized in such non-Hermitian systems. EP demonstrates a square root topology on minute perturbations, hence promising to be a potential candidate to sense external parameters, such as temperature, thermal fluctuations, refractive index, and biomolecules. Hence, in this work, through numerical and analytical investigations, we explore the sensing capabilities in the vicinity of EP utilizing suitably designed terahertz metasurfaces. Here, we propose a non-Hermitian metasystem comprising two orthogonally twisted square split ring resonators coupled by near-field EM (Electromagnetic) interactions that can exhibit dark-bright modes. In such a system, the presence of an active (photo-doped) material in the split gap of one of the resonators opens up an effective avenue to introduce controllable asymmetric losses, ultimately leading to the emergence of exceptional points in the polarization space. Hence, thin film sensing at the proximity of the emerged exceptional point is investigated for different refractive indices by coating with an overlayer atop the metasurface. In such a configuration, the sensitivities of the eigenstates are calculated in terms of the Refractive Index Unit, which turns out to be - 0.044 THz/RIU and - 0.063 THz/RIU when the system is perturbed near EP. Our proposed metasurface-inspired EP-based sensing strategy can open up novel ways to sense the refractive index of unknown materials besides other physical parameters.\",\"PeriodicalId\":508829,\"journal\":{\"name\":\"New Journal of Physics\",\"volume\":\" 5\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-04-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"New Journal of Physics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1088/1367-2630/ad3fe0\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Journal of Physics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1088/1367-2630/ad3fe0","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
非ermitian 量子系统与工程元表面为从工业到医疗领域的传感器设计提供了一个多功能平台。被称为 "例外点"(EP)的奇异点可以在此类非ermitian 系统中实现。EP 在微小扰动下表现出平方根拓扑结构,因此有望成为感知外部参数(如温度、热波动、折射率和生物分子)的潜在候选者。因此,在这项工作中,我们通过数值和分析研究,探索了利用适当设计的太赫兹元表面在 EP 附近的传感能力。在这里,我们提出了一种非ermitian 元系统,它由两个正交扭曲的方形分裂环谐振器组成,通过近场电磁(EM)相互作用耦合,可以表现出暗-亮模式。在这种系统中,其中一个谐振器的分裂间隙中存在活性(光掺杂)材料,为引入可控非对称损耗开辟了有效途径,最终导致极化空间中出现特殊点。因此,通过在元表面上涂覆一层覆盖层,研究了不同折射率下出现的异常点附近的薄膜传感。在这种配置中,特征状态的灵敏度是以折射率单位来计算的,当系统在超常点附近受到扰动时,灵敏度分别为 - 0.044 THz/RIU 和 - 0.063 THz/RIU。我们提出的基于元表面启发的 EP 传感策略可以为传感未知材料的折射率以及其他物理参数开辟新的途径。
Thin Film Sensing near Exceptional Point utilizing Terahertz Plasmonic Metasurfaces
Non-Hermitian quantum systems along with engineered metasurfaces enable a versatile podium for sensor designs from industrial to medical sectors. The singularity points known as Exceptional points (EP) can be realized in such non-Hermitian systems. EP demonstrates a square root topology on minute perturbations, hence promising to be a potential candidate to sense external parameters, such as temperature, thermal fluctuations, refractive index, and biomolecules. Hence, in this work, through numerical and analytical investigations, we explore the sensing capabilities in the vicinity of EP utilizing suitably designed terahertz metasurfaces. Here, we propose a non-Hermitian metasystem comprising two orthogonally twisted square split ring resonators coupled by near-field EM (Electromagnetic) interactions that can exhibit dark-bright modes. In such a system, the presence of an active (photo-doped) material in the split gap of one of the resonators opens up an effective avenue to introduce controllable asymmetric losses, ultimately leading to the emergence of exceptional points in the polarization space. Hence, thin film sensing at the proximity of the emerged exceptional point is investigated for different refractive indices by coating with an overlayer atop the metasurface. In such a configuration, the sensitivities of the eigenstates are calculated in terms of the Refractive Index Unit, which turns out to be - 0.044 THz/RIU and - 0.063 THz/RIU when the system is perturbed near EP. Our proposed metasurface-inspired EP-based sensing strategy can open up novel ways to sense the refractive index of unknown materials besides other physical parameters.