A5088368601- Plasmonic and Surface Plasmon Research
- Metamaterials and Metasurfaces Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Photonic Crystals and Applications
- Topological Materials and Phenomena
- Orbital Angular Momentum in Optics
- Near-Field Optical Microscopy
- Photonic and Optical Devices
- Random lasers and scattering media
- Quantum optics and atomic interactions
- Quantum Dots Synthesis And Properties
- Photoreceptor and optogenetics research
- Liquid Crystal Research Advancements
- Nanomaterials and Printing Technologies
- Molecular spectroscopy and chirality
- Molecular Junctions and Nanostructures
- Spectroscopy and Quantum Chemical Studies
- Quantum many-body systems
- Graphene research and applications
- Quantum Mechanics and Non-Hermitian Physics
- Advanced biosensing and bioanalysis techniques
- Mechanical and Optical Resonators
- Strong Light-Matter Interactions
- Spectroscopy Techniques in Biomedical and Chemical Research
- Quantum chaos and dynamical systems
Donostia International Physics Center
2016-2025
Ikerbasque
2012-2025
Max Planck Institute for Chemical Physics of Solids
2023
University of Illinois Urbana-Champaign
2023
Material Physics Center
2009-2020
Stanford University
2011-2015
Consejo Superior de Investigaciones Científicas
2008-2011
Université Paris-Sud
2010
CIC nanoGUNE
2010
Colorado State University
2006
A novel resonant mechanism involving the interference of a broadband plasmon with narrowband vibration from molecules is presented. With use this concept, we demonstrate experimentally enormous enhancement vibrational signals less than one attomol on individual gold nanowires, tailored to act as plasmonic nanoantennas in infrared. By detuning resonance via change antenna length, Fano-type behavior spectral signal observed, which clearly supported by full electrodynamical calculations. This...
High-permittivity dielectric particles with resonant magnetic properties are being explored as constitutive elements of new metamaterials and devices in the microwave regime. Magnetic low-loss nanoparticles visible or infrared not expected due to intrinsic low refractive index optical materials these regimes. Here we analyze dipolar electric response loss-less spheres made moderate permittivity materials. For material there no sharp resonances strong overlapping between different multipole...
The plasmon resonances of two closely spaced metallic particles have enabled applications including single-molecule sensing and spectroscopy, novel nanoantennas, molecular rulers, nonlinear optical devices. In a classical electrodynamic context, the strength such dimer increases monotonically as particle gap size decreases. contrast, quantum mechanical framework predicts that electron tunneling will strongly diminish for subnanometer-scale separations. Here, we directly observe coupled...
Upconversion, the conversion of photons from lower to higher energies, is a process that promises applications ranging high-efficiency photovoltaic and photocatalytic cells background-free bioimaging therapeutic probes. Existing upconverting materials, however, remain too inefficient for viable implementation. In this Perspective, we describe significant improvements in upconversion efficiency can be achieved using plasmon resonances. As collective oscillations free electrons, resonances...
Light scattering at nanoparticles and molecules can be dramatically enhanced in the 'hot spots' of optical antennas, where incident light is highly concentrated. Although this effect widely applied surface-enhanced sensing, spectroscopy microscopy, underlying electromagnetic mechanism signal enhancement challenging to trace experimentally. Here we study elastically scattered from an individual object located well-defined hot spot single as a new approach resolve role antenna process. We...
We theoretically investigate light matter interactions for chiral molecules in the presence of non-chiral nanoantennas. Isotropic nanostructures supporting optical-frequency electric or magnetic dipoles are sufficient to locally enhance excitation a molecule's polarizability and thus its circular dichroism spectrum. However, simultaneous necessary achieve net, spatially-averaged enhancement. Our contribution provides theoretical framework understand light-matter at nanoscale sets conditions...
Circularly polarized light (CPL) exhibits an enantioselective interaction with chiral molecules, providing a pathway toward all-optical resolution. High index dielectric nanoparticles have been shown to enhance this relationship, but spatially varying sign (or enantiospecificity) that yields near zero averaged enhancement. Using full field electromagnetic simulations, we design metasurfaces consisting of high disks provide large-volume, uniform-sign enhancements in both the optical density...
Axions, hypothetical elementary particles that remain undetectable in nature, can arise as quasiparticles three-dimensional crystals known axion insulators. Previous implementations of insulators have largely been limited to two-dimensional systems, leaving their topological properties three dimensions unexplored experiment. Here, we realize an insulator a photonic crystal and probe its properties. Demonstrated features include half-quantized Chern numbers on each surface resembles...
Assemblies of strongly coupled plasmonic nanoparticles can support highly tunable electric and magnetic resonances in the visible spectrum. In this Letter, we theoretically demonstrate Fano-like interference effects between fields radiated by modes symmetric nanoparticle trimers. Breaking symmetry trimer system leads to a strong interaction modes. The near far-field electromagnetic properties broken are across large spectral range. We exploit effect spatial temporal control localized hotspots trimer.
We demonstrate that the local near-field vector and polarization state on planar antenna structures in nanoscale gaps can be determined by scattering-type optical microscopy (s-SNOM). The is reconstructed from amplitude phase images of in- out-of-plane components obtained polarization-resolved interferometric detection. Experiments with a mid-infrared inverse bowtie yield vectorial distribution unprecedented resolution about 10 nm excellent agreement numerical simulations. Furthermore, we...
Separation of enantiomers is crucial to the pharmaceutical and chemical industries, but prevailing methods are economically costly time-consuming. Illumination with circularly polarized light (CPL) provides a potentially cost-effective versatile alternative can achieve only 2% enantiomeric excesses substantial yield. Here, we theoretically show that high-index dielectric nanoparticles increase 7 times beyond CPL in free space. Mie theory local optimization algorithm indicate magnetic...
Abstract Near‐field optical microscopy techniques provide information on the amplitude and phase of local fields in samples interest nanooptics. However, near field is typically obtained by converting it into propagating far where signal detected. This case, for instance, polarization‐resolved scattering‐type scanning near‐field (s‐SNOM), a sharp dielectric tip scatters off antenna to field. Up now, basic models have interpreted S ‐ P ‐polarized maps s‐SNOM as directly proportional in‐plane...
Abstract The field of topological photonics emerged as one the most promising areas for applications in transformative technologies: possible are lasers or quantum optics interfaces. Nevertheless, efficient and simple methods diagnosing topology optical systems remain elusive an important part community. Herein, a summary numerical to calculate invariants emerging from propagation light photonic crystals is provided. fundamental properties wave lattices with space‐dependent periodic electric...
Topological photonic crystals are promising optical devices for long-distance communication and signal processing. In this work, the authors show how theory of band representations--developed finding topological electronic materials--can be used to design characterize these new crystal structures. As an example, paper proposes a structure that realizes first time in non-interacting system newly-introduced idea fragile topology.
We identify weak and strong coupling regimes between a near-field probing tip plasmonic sample by imaging plasmon-resonant gold nanodisks with scattering-type scanning optical microscopy (s-SNOM). By means of rigorous electrodynamical calculations based on model system, we find that in the regime, s-SNOM can be applied for direct mapping nanoantenna modes, while probe allows high-precision opto-mechanical control antenna response.
We describe transmission-mode scattering-type near-field optical microscopy (s-SNOM) with interferometric detection. Using this technique, we map the modes of infrared antennas in both amplitude and phase. The use dielectric probing tips, higher-harmonic demodulation, a complex-valued subtraction residual background yields accurate images antenna modes. metallic nanorods, disks, triangles, designed for resonance at mid-infrared frequencies, good agreement numerical calculations modal field...
We study hybrid-molecule structures consisting of a metal nanoparticle (MNP) nanorod coupled to semiconductor quantum dot (SQD). MNP geometry can be used tailor the local fields that determine SQD-MNP coupling and engineer hybrid dynamical response. identify regimes where dark modes higher-order multipolar influence Strong local-field via changes interference self-interaction effects dramatically. External do not directly drive this mode, so is dominated by induced self-coupling. By...
We analyze the robustness of corner modes in topological photonic crystals, taking a C6-symmetric breathing honeycomb crystal as an example. First, we employ quantum chemistry and Wilson loop calculations to demonstrate that properties bulk stem from obstructed atomic limit phase. then characterize emerging within gapped edge employing semianalytical model, determining appropriate real-space invariants. provide detailed account effect long-range interactions on quantify their perturbations....
The directionality and polarization of light show peculiar properties when the scattering by a dielectric sphere can be described exclusively electric magnetic dipolar modes. Particularly, these modes oscillate in-phase with equal amplitude, at so-called first Kerker condition, zero optical backscattering condition emerges for non-dissipating spheres. However, role absorption gain in remains unexplored. In this work, we demonstrate that either or precludes and, hence, absence backscattered...
We study the non-trivial phase of two-dimensional breathing kagome lattice, displaying both edge and corner modes. The localized modes a flake were initially identified as signature higher-order topological but later shown to be trivial for perturbations that thought protect them. Using various theoretical simulation techniques, we confirm it does not display topology: are nature. Nevertheless, they might protected. First, show set within tight-binding model can move away from zero energy,...
Upconversion of sub-bandgap photons can increase the maximum efficiency a single-junction solar cell from 30% to over 44%. However, upconverting materials often have small absorption cross-sections and poor radiative recombination efficiencies that limit their utility in applications. Here, we show upconversion be substantially enhanced with suitably designed plasmonic nanostructure. The structure consists spherical nanocrescent composed an upconverter-doped dielectric core crescent-shaped...
A broadband metamaterial presenting negative indices across hundreds of nanometers in the visible and near‐infrared spectral regimes is demonstrated theoretically, using transformation optics to design constituents. The approach begins with an infinite plasmonic waveguide that supports a but dark (i.e, not easily optically accessed) index mode. Conformal mapping this finite split‐ring‐resonator‐type structure transforms mode into bright efficiently excited) resonance composed degenerate...