Article
Chemistry, Multidisciplinary
Jingang Li, Mingsong Wang, Zilong Wu, Huanan Li, Guangwei Hu, Taizhi Jiang, Jianhe Guo, Yaoran Liu, Kan Yao, Zhihan Chen, Jie Fang, Donglei Fan, Brian A. Korgel, Andrea Alu, Yuebing Zheng
Summary: A study has reported reconfigurable chiral nanostructures with silicon nanoparticles and nanowires, allowing for tailored configurations and chiroptical responses. The optical chirality arises from the coupling between optical resonances of the silicon nanoparticle and nanowire, enabling label-free enantiodiscrimination of biomolecules in single structures. This research provides insights into high-index material design and new strategies for adaptive devices in photonic and electronic applications.
Article
Mathematics, Applied
M. Erden Yildizdag, Bekir Cagri Sarar, Antonello Salvatori, Gino D'Ovidio, Emilio Turco
Summary: This paper investigates the linear wave propagation in pantographic lattices. The pantographic lattice is assumed to be attached to a classical first-gradient continuum with a structured interface. Governing equations and jump conditions at the structured interface are obtained using a variational principle. The effects of elastic moduli and material properties of both continua and the structured interface are analyzed through a parameter study.
ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK
(2023)
Article
Chemistry, Multidisciplinary
Yi Chen, Mahmoud A. A. Abouelatta, Ke Wang, Muamer Kadic, Martin Wegener
Summary: Introduces reconfigurable plug-and-play electromagnetic metamaterials, where the building blocks are standard bayonet Neill-Concelman (BNC) connectors and the effective properties are achieved by tailoring local and nonlocal interactions mediated by standard coaxial cables. Demonstrates unprecedented dispersion relations with multiple regions of slow waves and backward waves in the lowest band. Importantly, the dispersion relation of such metamaterials is not limited by causality as in the case of local resonances.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ali H. Alqahtani, Yosef T. Aladadi, Mohammed T. Alresheedi
Summary: This paper proposes a dielectric slabs-based lens for millimeter-wave beamforming systems. The lens consists of multiple dielectric slabs with matching gradient effective refractive index, same thicknesses, and different radii, used for millimeter-wave beamforming applications.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Multidisciplinary
Weifeng Jiang, Yangyang Zhu, Guofu Yin, Houhong Lu, Luofeng Xie, Ming Yin
Summary: This study establishes a mapping between the structural topology and the dispersion relation of elastic metamaterials using deep learning approaches. The proposed model accurately predicts the dispersion relation for a given structure and enables the inverse design of near-optimal structures based on the target dispersion relation. The deep learning-based approaches have shown capability in accelerating the design and optimization process, paving the way for new breakthroughs in metamaterials research.
MATERIALS TODAY PHYSICS
(2022)
Article
Engineering, Multidisciplinary
Ugur Cem Hasar, Yunus Kaya, Mucahit Izginli, Hamdullah Ozturk, Mehmet Ertugrul, Omar M. Ramahi
Summary: This study examines the coupling effects between Metamaterial (MM) slabs using signal flow graph technique and ABCD parameters, analyzing the coupling at different distances through simulated and measured scattering parameters. Experimental measurements of S-parameters on MM slabs validated the theoretical analysis.
Article
Physics, Multidisciplinary
Yangfeng Li, Wenqi Wang, Chen Yue, Xiaotao Hu, Yimeng Song, Zaole Su, Haiqiang Jia, Wenxin Wang, Yang Jiang, Hong Chen
Summary: The study obtained and analyzed the photo-generated currents of GaAs solar cells with different lengths of space charge region. The calculated currents based on enhanced absorption coefficient in the space charge region coincide well with experimental currents under both single wavelength incidence and solar spectrum irradiation conditions.
Article
Physics, Applied
Weiqi Cai, Yuancheng Fan, Quanhong Fu, Ruisheng Yang, Wei Zhu, Yujing Zhang, Fuli Zhang
Summary: In this work, a hybrid metamaterial exhibiting extraordinary optical transmission (EOT) behavior was theoretically and experimentally studied. The transmission amplitude and frequency can be modulated by utilizing the first-order Mie-resonant mode and the nonlinear effect of the dielectric cuboid.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Jing Chen, Chun Yang, Ping Gu, Yihan Kuang, Chaojun Tang, Siyu Chen, Zhengqi Liu
Summary: The study introduces a method to enhance the sensing properties of a 3D metamaterial sensor by combining magnetic plasmon resonance and a dielectric waveguide. The hybrid magnetic plasmon resonance formed by vertical split ring resonators and a propagating optical waveguide mode results in high sensitivity and figure of merit, making it suitable for label-free biosensing applications.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Jacob B. Khurgin
Summary: While the photonics community is focused on exotic concepts, the simple idea of increasing the refractive index may have greater potential in various applications. The author explores why higher index materials have not yet been developed and suggests some tentative directions for finding these elusive materials, whether natural or artificial.
Article
Chemistry, Physical
Victoria Esteso, Sol Carretero-Palacios, Hernan Miguez
Summary: We study quantum trapping effects in planar nanocomposite materials and find that they strongly depend on the characteristics of spatial inhomogeneity. The presence of inclusions leads to intense repulsive Casimir-Lifshitz force due to strong optical scattering and absorption size-dependent resonances. Comprehensive knowledge and a detailed description of the potential inhomogeneity in materials are necessary for analyzing quantum trapping effects.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Octavian Danila, Ana Barar, Marian Vladescu, Doina Manaila-Maximean
Summary: This paper introduces a k-surface framework for describing the dispersion properties of media with designer electric and magnetic responses, including positive and negative values as well as the coupling between the two.
Article
Chemistry, Physical
Yi An, Han Zou, Aiguo Zhao
Summary: This paper proposes an acoustic metastructure with a composite structure that can manipulate the wavefront in sub-wavelength dimensions and considers both wavefront manipulation and sound absorption for underwater acoustic stealth. By gradually modulating the equivalent physical properties along the horizontal direction, the incident acoustic wave is reflected to other directions, and the polymer material inside the unit cells dissipates the acoustic wave energy due to its inherent damping properties, leading to a significant improvement in the underwater stealth effect. Compared to a single-phase metastructure, the multiphase metastructure reduces the Far-Field Sound Pressure Level (FFSPL) by 4.82 dB within the frequency range of 3 kHz to 30 kHz. The proposed composite structure has potential applications due to its acceptable thickness (80 mm) and low equivalent density (1100 kg/m(3)).
Article
Chemistry, Physical
Chi Wang, Yuming Feng, Junjie Zhou, Guangwu Wen, Long Xia
Summary: Non-magnetic materials have great potential in microwave absorption, but analyzing the connection between performance and parameters is still challenging. This study simplifies and derives formulae, establishes criteria and fitting methods, and investigates the electromagnetic parameters for absorbing performance.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Optics
C. Belabed, A. Tab, B. Belhamdi, S. Boudiaf, B. Bellal, N. Benrekaa, M. Trari
Summary: The study focuses on developing visible-light active Pani-ZnO nanoparticles through in situ polymerization, which showed improved photoactivity compared to Pani alone. By analyzing the optical and dielectric properties, the research provides further insights into the charge transfer and electronic properties of Pani-ZnO nanoparticles.
Article
Optics
Korbinian J. Kaltenecker, Shreesha D. S. Rao, Mattias Rasmussen, Henrik B. Lassen, Edmund J. R. Kelleher, Enno Krauss, Bert Hecht, N. Asger Mortensen, Lars Gruener-Nielsen, Christos Markos, Ole Bang, Nicolas Stenger, Peter Uhd Jepsen
Summary: This study developed a low-noise supercontinuum (SC) source for high resolution, spectrally resolved near-field measurements in the near-infrared (NIR) region. The SC light source was used to demonstrate the first NIR, spectrally resolved s-SNOM measurement and characterize the dispersion curve of surface plasmon polariton (SPP) waves in the NIR, representing a technological breakthrough for potential new applications in near-field studies.
Review
Nanoscience & Nanotechnology
Sergey G. Menabde, Jacob T. Heiden, Joel D. Cox, N. Asger Mortensen, Min Seok Jang
Summary: Polaritonic modes in low-dimensional materials enable strong light-matter interactions and the manipulation of light on nanometer length scales. The recent interest in image polaritons in van der Waals crystals has gained considerable attention in nanophotonics, where a polaritonic material couples with its mirror image in close proximity to a highly conductive metal. These image modes provide an appealing nanophotonic platform with lower propagation loss and access to the nonlocal regime of light-matter interaction.
Article
Chemistry, Multidisciplinary
Saskia Fiedler, P. Elli Stamatopoulou, Artyom Assadillayev, Christian Wolff, Hiroshi Sugimoto, Minoru Fujii, N. Asger Mortensen, Soren Raza, Christos Tserkezis
Summary: Cathodoluminescence spectroscopy in an electron microscope is a versatile tool for analyzing the optical response of plasmonic and dielectric nanostructures. However, the transition radiation produced by electron impact is often neglected. This study demonstrates that transition radiation can generate distinct resonances that interfere constructively or destructively depending on the electron beam's time-of-flight inside the nanosphere, leading to distorted spectra and potentially erroneous modal assignment.
Article
Optics
Antton Babaze, Eduardo Ogando, P. Elli Stamatopoulou, Christos Tserkezis, N. Asger Mortensen, Javier Aizpurua, Andrei G. Borisov, Ruben Esteban
Summary: In this study, time-dependent density functional theory (TDDFT) was used to investigate the impact of quantum-mechanical effects on the self-interaction Green's function, which governs the electromagnetic interaction between quantum emitters and plasmonic metallic nanoantennas. The results reveal that quantum effects, such as surface-enabled Landau damping and the spill out of induced charges, strongly influence the nanoantenna-emitter interaction, leading to a redshift and broadening of plasmonic resonances. These effects are not considered in classical theories that assume a local dielectric response of the metals.
Article
Multidisciplinary Sciences
Sergejs Boroviks, Zhan-Hong Lin, Vladimir A. Zenin, Mario Ziegler, Andrea Dellith, P. A. D. Goncalves, Christian Wolff, Sergey Bozhevolnyi, Jer-Shing Huang, N. Asger Mortensen
Summary: Nonlocal effects in propagating gap surface plasmon modes in ultrathin metal-dielectric-metal planar waveguides are investigated using scanning near-field optical microscopy. Experimental results show the signatures of nonlocal damping in few-nanometer-sized dielectric gaps.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Sergey G. Menabde, Sergejs Boroviks, Jongtae Ahn, Jacob T. Heiden, Kenji Watanabe, Takashi Taniguchi, Tony Low, Do Kyung Hwang, N. Asger Mortensen, Min Seok Jang
Summary: This research uses large-area monocrystalline gold flakes as a low-loss substrate for image polaritons, accurately measures the complex propagation constant of polaritons in van der Waals crystals, and finds that the propagation loss and normalized propagation length of image phonon-polaritons have specific spectral dependencies.
Article
Materials Science, Multidisciplinary
Sergey G. Menabde, Junghoon Jahng, Sergejs Boroviks, Jongtae Ahn, Jacob T. Heiden, Do Kyung Hwang, Eun Sung Lee, N. Asger Mortensen, Min Seok Jang
Summary: Orthorhombic molybdenum trioxide (alpha-MoO3) is a polaritonic van der Waals crystal with strongly anisotropic mid-infrared phonon-polaritons. The coupling of polariton with its mirror image in an adjacent metal leads to a more confined image mode. This research measures the propagation constant of image phonon-polaritons in alpha-MoO3 using monocrystalline gold flakes as a substrate, demonstrating the long lifetime and propagation length of these polaritons.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Sergii Morozov, Stefano Vezzoli, Alina Myslovska, Alessio Di Giacomo, N. Asger Mortensen, Iwan Moreels, Riccardo Sapienza
Summary: Giant shell CdSe/CdS quantum dots exhibit high brightness and flexibility, with near-unity quantum yield and suppressed blinking. However, their single photon purity is reduced due to efficient multiexcitonic emission. In this study, we observed a significant blueshift in the photoluminescence biexciton spectrum of pure-phase wurtzite quantum dots. By using spectral filtering, we achieved a 2.3 times reduction in biexciton quantum yield while preserving 60% of the exciton single photon emission, leading to an improvement in purity from g2(0)=0.07±0.01 to g2(0)=0.03±0.01. Furthermore, at higher pump fluence, the spectral purification was even more effective, resulting in up to a 6.6 times reduction in g2(0) by suppressing higher order excitons and shell states with larger blueshifts.
Article
Nanoscience & Nanotechnology
Alvaro Rodriguez Echarri, Fadil Iyikanat, Sergejs Boroviks, N. Asger Mortensen, Joel D. Cox, F. Javier Garcia de Abajo
Summary: The promising applications of photonics rely on the fabrication of high-quality metal thin films with controlled thickness in the range of a few nanometers. These materials exhibit highly nonlinear response to optical fields due to ultrafast electron dynamics. However, the understanding of this phenomenon on such small length scales is limited. In this study, a new mechanism controlling the nonlinear optical response of thin metallic films is revealed, which is dominated by ultrafast electronic heat transport when the film thickness is sufficiently small. By experimentally and theoretically studying electronic transport in these materials, the researchers explained the observed temporal evolution of photoluminescence in two-pulse correlation measurements. They found that ultrafast thermal dynamics plays a crucial role in determining the strength and time-dependent characteristics of the nonlinear photoluminescence signal. Their findings provide new insights into the nonlinear optical response of nanoscale materials and offer possibilities for controlling and utilizing hot carrier distributions in metallic films.
Article
Materials Science, Multidisciplinary
Saskia Fiedler, Sergii Morozov, Leonid Iliushyn, Sergejs Boroviks, Martin Thomaschewski, Jianfang Wang, Timothy J. Booth, Nicolas Stenger, Christian Wolff, N. Asger Mortensen
Summary: Cathodoluminescence spectroscopy combined with second-order auto-correlation measurements of g(2)(tau) allows for extensive study of the synchronization of photon emitters in low-dimensional structures. Co-existing excitons in two-dimensional transition metal dichalcogenide monolayers serve as a great source of identical photon emitters that can be simultaneously excited by an electron. In this study, we demonstrate large photon bunching with g(2)(0) up to 156 +/- 16 in a tungsten disulfide monolayer (WS2), showing a strong dependence on the electron-beam current. By carefully selecting a simple and compact geometry, such as a thin monocrystalline gold nanodisk, we achieve a record-high bunching g(2)(0) of up to 2152 +/- 236, improving the excitation synchronization and electron-emitter interaction. This approach of controlling electron excitation of excitons in a WS2 monolayer enables the synchronization of photon emitters in an ensemble, which is crucial for advancing light information and computing technologies.
Article
Nanoscience & Nanotechnology
Saskia Fiedler, Sergii Morozov, Danylo Komisar, Evgeny A. A. Ekimov, Liudmila F. F. Kulikova, Valery A. A. Davydov, Viatcheslav N. N. Agafonov, Shailesh Kumar, Christian Wolff, Sergey I. I. Bozhevolnyi, N. Asger Mortensen
Summary: Impurity-vacancy centers in diamond provide a class of robust photon sources with versatile quantum properties. The ensembles of color centers have tunable photon-emission statistics and their emission properties can be controlled by different types of excitation. Electron-beam excitation can synchronize the emitters' excitation and control the second-order correlation function g(2)(0), as confirmed by experimental results in this letter. Such a photon source based on an ensemble of few color centers in a diamond crystal offers a highly tunable platform for room temperature informational technologies.
Article
Optics
Christos Tserkezis, Christian Wolff, Fedor A. Shuklin, Francesco Todisco, Mikkel H. Eriksen, P. A. D. Goncalves, N. Asger Mortensen
Summary: We propose an efficient approach for actively controlling the Rabi oscillations in nanophotonic emitter-cavity analogs based on the presence of an element with optical gain. Inspired by recent developments in parity-time (PT)-symmetry photonics, we show that nano-or microcavities where intrinsic losses are partially or fully compensated by an externally controllable amount of gain offer unique capabilities for manipulating the dynamics of extended (collective) excitonic emitter systems. Furthermore, we show that there is a specific gain value that leads to an exceptional point, where both the emitter and cavity occupation oscillate practically in phase, with occupation numbers that can significantly exceed unity.
Article
Materials Science, Multidisciplinary
Gino Wegner, Dan-Nha Huynh, N. Asger Mortensen, Francesco Intravaia, Kurt Busch
Summary: The paper discusses the impact of an extended model proposed by Halevi on the nonlocal response of plasmonic materials and nanostructures. It reevaluates the Mie scattering coefficients for a cylinder and corresponding plasmon-polariton resonances within this framework. The analysis reveals a nonlocal, collisional, and size-dependent damping term that affects the resonances in the extinction spectrum. The implementation of the Halevi model in the time domain is particularly important for efficient and accurate modeling of nanogap structures and other nanoscale features in nanoplasmonics applications.
Article
Chemistry, Multidisciplinary
P. Elli Stamatopoulou, Sotiris Droulias, Guillermo P. Acuna, N. Asger Mortensen, Christos Tserkezis
Summary: This paper introduces and analyzes the concept of manipulating optical chirality by strongly coupling the optical modes of chiral nanostructures with excitonic transitions in molecular layers or semiconductors. By demonstrating the generation of two spectral branches that retain the object's high chirality density through strong coupling with a nearby excitonic material, the authors propose that post-fabrication manipulation of optical chirality can be achieved. These findings are further verified through simulations of circular dichroism in a realistic chiral architecture.
Article
Optics
F. A. Shuklin, C. Tserkezis, N. Asger Mortensen, C. Wolff
Summary: This study analyzes the emergence of unphysical superluminal group velocities in Su-Schrieffer-Heeger (SSH) parity-time (PT) symmetric chains and explores the origins of this behavior. The analysis reveals that material dispersion is the key factor causing the divergence of group velocities. Restoring causality resolves the issue and sets practical limits on the performance of PT-symmetric systems.
