Article
Nanoscience & Nanotechnology
Junais Habeeb Mokkath
Summary: Using first-principles simulations, this study investigates the modifications in absorption spectra and electric near-field enhancements in a structure consisting of an aluminum nanotriangle interacting with pyridine molecules. The results reveal interesting spatial variations in induced electron density and electric near-field enhancements, depending on the number of interacting pyridine molecules and the direction of light illumination. This contributes to a better understanding of the light-matter interaction at the sub-nanometer scale.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Physics, Applied
M. Hrytsaienko, M. Gallart, M. Ziegler, O. Cregut, S. Tamariz, R. Butte, N. Grandjean, B. Hoenerlage, P. Gilliot
Summary: This work investigates the photoluminescence properties of c-plane GaN/AlN quantum dot ensembles, revealing the existence of a relaxation channel competing with radiative recombination, and finding that the nonradiative transfer process is independent of the dot height, while the radiative recombination process depends on the emission energy characteristics.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Multidisciplinary Sciences
Shuai Zhang, Baichang Li, Xinzhong Chen, Francesco L. Ruta, Yinming Shao, Aaron J. Sternbach, A. S. McLeod, Zhiyuan Sun, Lin Xiong, S. L. Moore, Xinyi Xu, Wenjing Wu, Sara Shabani, Lin Zhou, Zhiying Wang, Fabian Mooshammer, Essance Ray, Nathan Wilson, P. J. Schuck, C. R. Dean, A. N. Pasupathy, Michal Lipson, Xiaodong Xu, Xiaoyang Zhu, A. J. Millis, Mengkun Liu, James C. Hone, D. N. Basov
Summary: Excitons play a dominant role in the optoelectronic properties of atomically thin semiconductors. In this study, the authors used a scanning near-field optical microscope (s-SNOM) to characterize the exciton spectra and complex dielectric function of 2D transition metal dichalcogenides with previously unattainable resolution. The results provide insights into the spatial dependence of excitons and pave the way for their manipulation at the nanoscale.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Xujie Wang, Chi Zhang, Fangqi Chen, Junxiang Xiang, Shuangshuang Wang, Ze Liu, Tao Ding
Summary: Photons can be used as clean and abundant energy carriers for nanoactuation, but the response is often slow and energy efficiency is low. This study introduces the concept of robust nanoscale plasmonic dynamite using fullerene (C-60) incorporated nanoparticles, which can explode in nanoscale with the help of plasmon-enhanced photochemical and photothermal effects. This nanoexplosion generates powerful forces and high thermomechanical energy efficiency, making it a promising nanoengine for controlled mobilization of micro-objects on solid surfaces. Such nanoscale plasmonic dynamite can be utilized in various types of nanomachines, providing a powerful energy source for nanoactuation and nanomigration.
Article
Optics
Mohsen Samadi, Pooya Alibeigloo, Abolfazl Aqhili, Mohammad Ali Khosravi, Farahnaz Saeidi, Shoaib Vasini, Mostafa Ghorbanzadeh, Sara Darbari, Mohammad Kazem Moravvej-Farshi
Summary: Plasmonic tweezers are indispensable tools for manipulating micro and nano-objects with high precision, utilizing surface plasmon technology to trap particles beyond the diffraction limit. Trapping-potential landscape can be reconfigured by designing plasmonic nanostructures.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Multidisciplinary Sciences
Artem N. Abramov, Igor Y. Chestnov, Ekaterina S. Alimova, Tatiana Ivanova, Ivan S. Mukhin, Dmitry N. Krizhanovskii, Ivan A. Shelykh, Ivan V. Iorsh, Vasily Kravtsov
Summary: By using local deformation of monolayer WSe2, we have successfully created high-purity single-photon emitters. Through nanoindentation and atomic force microscopy, we have identified the single-photon emitting sites and reconstructed the details of the surrounding local strain potential. The experimental results suggest that the single-photon emission is likely due to strain-induced spectral shift of dark excitonic states and their hybridization with localized states of individual defects.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Pratiksha D. Dongare, Yage Zhao, David Renard, Jian Yang, Oara Neumann, Jordin Metz, Lin Yuan, Alessandro Alabastri, Peter Nordlander, Naomi J. Halas
Summary: A three-dimensional antennareactor geometry is demonstrated to induce large nanoscale thermal gradients, resulting in significant local temperature increases in the confined nanostructure reactor while minimizing temperature increase of the surrounding antenna. This strategy allows for high local temperature increases of nominally 200 degrees C achievable within antenna-reactors patterned into large extended arrays, which could have applications in small-volume, high-throughput chemical processes.
Article
Optics
Wei Fang, Congjie Ou, Gao-xiang Li, Yaping Yang
Summary: In this study, the resonance fluorescence properties of a driven cascaded exciton-biexciton quantum dot coupled to two-dimensional black phosphorus metasurfaces were investigated. It was found that the surface plasmon modes exhibited both elliptic and hyperbolic dispersion patterns depending on the carrier concentration. Unequal enhancements in the spontaneous decay of orthogonal in-plane dipoles were observed. By manipulating the anisotropy of the surfaces, the steady-state properties of the driven quantum dot could be highly tunable, leading to strong modifications in the resonance fluorescence. Two-mode noise spectra squeezing with different resonances and polarizations could be observed under certain conditions. The introduction of gate doping could enhance the two-mode squeezing, albeit at the expense of declines in photon-sideband detunings. The proposal presented in this study can be extended to other hybrid systems with anisotropic metasurfaces, which are essential for the development of quantum information science.
Article
Physics, Applied
Chao Guo, Jia-Bin You, Zhanxu Chen, Wenbo Zhang, Qian Zhao, Zhang-Kai Zhou
Summary: Plasmonic nanostructures, such as hyperbolic nanorods (HNR) proposed in this paper, offer the advantage of tunable photonic resonant modes and low loss, leading to a higher Purcell factor when coupled with resonant quantum emitters. HNR/QE hybrids also demonstrate superiority over traditional plasmonic nanorods in generating strong coupling and quantum entanglement.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Dmitry Makarov, Ksenia Makarova, Yuliana Tsykareva, Sergey Kapustin, Anastasia Kharlamova, Eugeny Gusarevich, Andrey Goshev
Summary: This paper investigates the theory of nanoscale waveguide beam splitters, revealing significant differences from larger scale devices and presenting the previously known theory as a special case. The analysis of the wave function at the output ports of the nanoscale beam splitter shows sensitivity to the size of the beam splitter, coupling parameter of the two waveguides, and the degree of nonmonochromaticity of the photons entering the splitter. These findings are important for quantum technologies utilizing nanosized beam splitters.
Article
Chemistry, Multidisciplinary
Hannah L. Weaver, Cora M. Went, Joeson Wong, Dipti Jasrasaria, Eran Rabani, Harry A. Atwater, Naomi S. Ginsberg
Summary: Understanding and leveraging the fundamental properties of semiconductors at the nanoscale requires characterizing how electronic and thermal energy transduce and transport. We demonstrate a method using stroboscopic optical scattering microscopy to simultaneously map heat and exciton populations in MoS2, enabling direct and quantitative discernment of different energy types.
Article
Multidisciplinary Sciences
Gonzalo Alvarez-Perez, Jiahua Duan, Javier Taboada-Gutierrez, Qingdong Ou, Elizaveta Nikulina, Song Liu, James H. Edgar, Qiaoliang Bao, Vincenzo Giannini, Rainer Hillenbrand, Javier Martin-Sanchez, Alexey Yu Nikitin, Pablo Alonso-Gonzalez
Summary: This article introduces a negative reflection optical phenomenon and directly visualizes polaritons at the nano scale. The research findings show that negative reflection can tune the wavelength and direction of polaritons, providing a new approach for realizing nanophotonics in low-loss natural media.
Article
Multidisciplinary Sciences
Hyeongwoo Lee, Yeonjeong Koo, Shailabh Kumar, Yunjo Jeong, Dong Gwon Heo, Soo Ho Choi, Huitae Joo, Mingu Kang, Radwanul Hasan Siddique, Ki Kang Kim, Hong Seok Lee, Sangmin An, Hyuck Choo, Kyoung-Duck Park
Summary: In this study, the authors present a method for all-optical control of exciton-to-trion conversion and its spatial distribution in a monolayer of MoS2. They induce a nanoscale strain gradient in a 2D crystal on a lateral MIM waveguide and use propagating SPPs to localize hot electrons, facilitating complete exciton-to-trion conversion even at ambient conditions. The SPP mode is modulated using adaptive wavefront shaping, enabling reversible all-optical control of the exciton-to-trion conversion rate and trion distribution.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Peng Xie, Yihan Cheng
Summary: Bound state in the continuum (BIC) in all-dielectric metasurfaces can enhance light-matter interactions in the mid-infrared range. The coupling between symmetry-protected BIC modes and PMMA molecular vibrations is demonstrated, with a flexible tuning of the coupling strength. The proposed hybrid system provides a promising platform for the fundamental study of light-matter interactions and potential applications in high-compact nanophotonic devices in mid-infrared frequencies.
Article
Nanoscience & Nanotechnology
Junais Habeeb Mokkath
Summary: The localized and intense field confinement near metallic plasmonic nanostructures has led to breakthrough applications in sensing and single-molecule detection. Quantum mechanical calculations of a cube-shaped nanoparticle cluster made of eight identical metal nanoparticles show sensitivity in absorption profile, response charge density, and field enhancements to interparticle gap distance. The emergence of charge-transfer plasmons and electron tunnelling mediated plasmons were revealed, providing quantitative access to field enhancements and potential design insights for new optical devices using close-packed nanoparticle clusters.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Review
Chemistry, Multidisciplinary
Xiangdong Guo, Wei Lyu, Tinghan Chen, Yang Luo, Chenchen Wu, Bei Yang, Zhipei Sun, F. Javier Garcia de Abajo, Xiaoxia Yang, Qing Dai
Summary: 2D monolayers can be vertically stacked in van der Waals heterostructures to support a wide range of confined polaritons. This offers advantages in terms of controlling the constituent layers, stacking sequence, and twist angles. These heterostructures have extended the performance and functions of polaritons, and potential applications include nanophotonic integrated circuits.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Theis P. P. Rasmussen, A. Rodriguez Echarri, F. Javier Garcia de Abajo, Joel D. D. Cox
Summary: The subwavelength plasmonic near-field enhancement is hindered by large ohmic losses in good plasmonic materials, while conventional phase-matching of fields in bulk nonlinear crystals is not suitable for realizing nonlinear optical phenomena on the nanoscale. In contrast, highly-doped graphene supports long-lived, highly-confined, and actively-tunable plasmons, making it an excellent platform for both plasmonics and nonlinear optics. By interfacing multiple graphene nanostructures in close proximity, we can trigger nonlocal effects associated with large gradients in the electromagnetic near field to enhance nonlinear response.
Article
Optics
Xihang Shi, Michael Shentcis, Yaniv Kurman, Liang Jie Wong, F. Javier Garcia de Abajo, Ido Kaminer
Summary: The tunable control of X-ray waves is a critical challenge for applications in X-ray spectroscopy, medical imaging, and radiation therapy. The proposed method of shaping X-ray waves directly at the source using strain on van der Waals materials has the potential to bypass the limits of current X-ray optics technology and enable further developments in high-resolution X-ray science.
Article
Chemistry, Multidisciplinary
Ivan Madan, Eduardo J. C. Dias, Simone Gargiulo, Francesco Barantani, Michael Yannai, Gabriele Berruto, Thomas LaGrange, Luca Piazza, Tom T. A. Lummen, Raphael Dahan, Ido Kaminer, Giovanni Maria Vanacore, F. Javier Garcia de Abajo, Fabrizio Carbone
Summary: Understanding and actively controlling the dynamics of nonequilibrium electron clouds is crucial for various applications. However, these clouds evolve in a complex manner on small scales, making them difficult to study. In this study, we use an ultrafast transmission electron microscope to solve the challenge of characterizing the evolution of electron clouds generated on metallic structures, providing insights into their intricate mechanisms and dynamics. This technique, known as charge dynamics electron microscopy (CDEM), opens up possibilities for studying a wide range of nonequilibrium electrodynamic phenomena on the nanoscale.
Article
Physics, Multidisciplinary
F. Javier Garcia de Abajo, Claus Ropers
Summary: The modulation of free electrons with light has been found to be effective in producing attosecond electron wave packets. However, existing research mainly focuses on manipulating the longitudinal wave function component, with limited attention given to the transverse degrees of freedom for temporal shaping. In this study, by utilizing parallel light-electron interactions in separate zones, we demonstrate the simultaneous spatial and temporal compression of a convergent electron wave function, resulting in the formation of sub-angstrom focal spots of attosecond duration. This approach opens up new possibilities for exploring ultrafast atomic-scale phenomena, particularly in attosecond scanning transmission electron microscopy.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Hai Hu, Na Chen, Hanchao Teng, Renwen Yu, Mengfei Xue, Ke Chen, Yuchuan Xiao, Yunpeng Qu, Debo Hu, Jianing Chen, Zhipei Sun, Peining Li, F. Javier Garcia de Abajo, Qing Dai
Summary: Negative refraction is achieved using hybrid topological polaritons in van der Waals heterostructures, allowing for gate-tunable manipulation of mid-infrared radiation. Wide-angle negatively refracted polaritons are observed in partially decorated a-MoO3 films with graphene, demonstrating reversible nanoscale focusing. This technique offers possibilities for electrically tunable super-resolution imaging, nanoscale thermal manipulation, enhanced molecular sensing, and on-chip optical circuitry.
Article
Optics
Xihang Shi, Yaniv Kurman, Michael Shentcis, Liang Jie Wong, F. Javier Garcia de Abajo, Ido Kaminer
Summary: The science and technology of X-ray optics have made significant progress, allowing for the focusing of X-rays in various applications. However, certain forms of tailoring waves that are common in the optical regime have been challenging to achieve in the X-ray regime. We propose a novel concept of X-ray focusing by inducing a curved wavefront during the X-ray generation process, enabling the creation of nanobeams with precise focal spots. This concept bypasses the limitations of traditional X-ray optical components and allows for tunable parameters of the focused hotspot.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Izzah Machfuudzoh, Tatsuki Hinamoto, F. Javier Garcia de Abajo, Hiroshi Sugimoto, Minoru Fujii, Takumi Sannomiya
Summary: This study fills the research gap in direct imaging of optical modes by demonstrating nanoscale optical-field visualization of self-interference of light extracted from excited modes through experimentally obtained photon maps that directly portray the field distributions of the excited eigenmodes. By selectively choosing specific modes using cathodoluminescence-based scanning transmission electron microscopy with angle-, polarization-, and wavelength-resolved capabilities, the internal field distributions of the whispering-gallery modes reveal the interference between multiple modes and the resulting complex patterns dependent on the detection angle and polarization. The direct visualization of internal fields enables a comprehensive understanding of WGMs and can provide insights for the design of nanophotonic applications.
Article
Nanoscience & Nanotechnology
Andrea Konecna, Enzo Rotunno, Vincenzo Grillo, F. Javier Garcia de Abajo, Giovanni Maria Vanacore
Summary: Single-pixel imaging was developed as a technique for probing with light wavelengths undetectable by conventional multi-pixel detectors. However, the spatial resolution of optics-based single-pixel microscopy is limited to hundreds of nanometers due to diffraction. In this study, we propose using optically modulated electrons in ultrafast electron microscopes to achieve subnanometer spatially and temporally resolved single-pixel imaging. Simulation results show that realistic imperfect illumination patterns can be used to reconstruct the sample image and its temporal evolution. Electron single-pixel imaging holds great potential for low-dose probing of beam-sensitive biological and molecular samples, particularly in rapid screening during in situ experiments.
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
Multidisciplinary Sciences
John H. Gaida, Hugo Lourenco-Martins, Sergey V. Yalunin, Armin Feist, Murat Sivis, Thorsten Hohage, F. Javier Garcia de Abajo, Claus Ropers
Summary: The paper introduces Lorentz-PINEM for full-field, non-invasive imaging of complex optical near fields at high spatial resolution. The authors use energy-filtered defocus phase-contrast imaging and iterative phase retrieval to reconstruct the phase distribution of interfering surface-bound modes on a plasmonic nanotip. Their approach is applicable for retrieving the spatially varying phase of nanoscale fields and topological modes.
NATURE COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Alejandro Manjavacas, F. Javier Garcia de Abajo
Summary: Single-photon emitters are essential for quantum technologies, but generating single photons along specific directions usually requires complex configurations. In this study, we propose a photon source that can efficiently generate single photons along guided modes. By placing a quantum emitter in a periodically patterned linear waveguide, the emission of photons is preferentially directed along the waveguide in a region close to the period, resulting in a significant reduction in temporal uncertainty. Our research opens up a new approach for producing highly directional single photons with reduced temporal uncertainty.
Article
Chemistry, Multidisciplinary
P. A. D. Goncalves, F. Javier Garcia de Abajo
Summary: This study theoretically demonstrates that core-level photoemission from nanostructures can exhibit spectrally narrow plasmonic features with relatively high probabilities analogous to the direct peak. The morphology and dimensionality of the nanostructures have a dramatic effect on the plasmon-satellite probabilities, and universal scaling laws are found. Additionally, a pump-probe scheme is introduced to explore the ultrafast dynamics of the sampled nanostructure by optically exciting plasmons prior to photoemission.
Article
Physics, Multidisciplinary
Lu Wang, F. Javier Garcia de Abajo, Georgia T. Papadakis
Summary: In this article, the violation of Kirchhoff's law is achieved in pattern-free heterostructures. It is demonstrated that a resonant mode in a dielectric spacer between a nonreciprocal film and a back reflector is sufficient to maximally violate Kirchhoff's law. The minimal dielectric requirements for such functionality are identified and currently available materials satisfy these requirements.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Eduardo J. C. Dias, Ivan Madan, Simone Gargiulo, Francesco Barantani, Michael Yannai, Giovanni Maria Vanacore, Ido Kaminer, Fabrizio Carbone, F. Javier Garcia de Abajo
Summary: We develop a comprehensive microscopic theory to predict the spatiotemporal dynamics of laser-pulse-induced plasmas, and study the characteristics of terahertz fields generated through electron emission, metal screening, and plasma cloud interactions. We also investigate the interaction with femtosecond electron beams and explain recent ultrafast electron microscopy experiments. Our work contributes fundamental insight into the generation and dynamics of micron-scale electron plasmas and their interaction with ultrafast electron pulses.
NANOSCALE ADVANCES
(2023)
