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Liu T, Ou JY, Papasimakis N, MacDonald KF, Gusev VE, Zheludev NI. Ballistic dynamics of flexural thermal movements in a nanomembrane revealed with subatomic resolution. Sci Adv 2022; 8:eabn8007. [PMID: 35984884 PMCID: PMC9390981 DOI: 10.1126/sciadv.abn8007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/07/2022] [Indexed: 05/26/2023]
Abstract
Flexural oscillations of freestanding films, nanomembranes, and nanowires are attracting growing attention for their importance to the fundamental physical and optical properties and device applications of two-dimensional and nanostructured (meta)materials. Here, we report on the observation of short-time scale ballistic motion in the flexural mode of a nanomembrane cantilever, driven by thermal fluctuation of flexural phonons, including measurements of ballistic velocities and displacements performed with subatomic resolution, using a free electron edge-scattering technique. Within intervals <10 μs, the membrane moves ballistically at a constant velocity, typically ~300 μm/s, while Brownian-like dynamics emerge for longer observation periods. Access to the ballistic regime provides verification of the equipartition theorem and Maxwell-Boltzmann statistics for flexural modes and can be used in fast thermometry and mass sensing during atomic absorption/desorption processes on the membrane.
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Affiliation(s)
- Tongjun Liu
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Nikitas Papasimakis
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Kevin F. MacDonald
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Vitalyi E. Gusev
- Laboratoire d’Acoustique de l’Université du Mans (LAUM), Institut d’Acoustique-Graduate School (IA-GS), CNRS, Le Mans Université, 72085 Le Mans, France
| | - Nikolay I. Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
- Centre for Disruptive Photonic Technologies and The Photonics Institute, SPMS, Nanyang Technological University, 637371, Singapore
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2
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Shen Y, Hou Y, Papasimakis N, Zheludev NI. Supertoroidal light pulses as electromagnetic skyrmions propagating in free space. Nat Commun 2021; 12:5891. [PMID: 34625539 PMCID: PMC8501108 DOI: 10.1038/s41467-021-26037-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/31/2021] [Indexed: 11/09/2022] Open
Abstract
Topological complex transient electromagnetic fields give access to nontrivial light-matter interactions and provide additional degrees of freedom for information transfer. An important example of such electromagnetic excitations are space-time non-separable single-cycle pulses of toroidal topology, the exact solutions of Maxwell's equations described by Hellwarth and Nouchi in 1996 and recently observed experimentally. Here we introduce an extended family of electromagnetic excitation, the supertoroidal electromagnetic pulses, in which the Hellwarth-Nouchi pulse is just the simplest member. The supertoroidal pulses exhibit skyrmionic structure of the electromagnetic fields, multiple singularities in the Poynting vector maps and fractal-like distributions of energy backflow. They are of interest for transient light-matter interactions, ultrafast optics, spectroscopy, and toroidal electrodynamics.
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Affiliation(s)
- Yijie Shen
- Optoelectronics Research Centre, Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Yaonan Hou
- Optoelectronics Research Centre, Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
| | - Nikitas Papasimakis
- Optoelectronics Research Centre, Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
| | - Nikolay I Zheludev
- Optoelectronics Research Centre, Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK.,Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore, 637378, Singapore
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3
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Li H, Ou JY, Fedotov VA, Papasimakis N. Decay rate enhancement of diamond NV-centers on diamond thin films. Opt Express 2021; 29:25626-25631. [PMID: 34614889 DOI: 10.1364/oe.425706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate experimentally two-fold enhancement of the decay rate of NV° centers on diamond/Si substrate as opposed to a bare Si substrate. We link the decay enhancement to the interplay between the excitation of substrate modes and the presence of non-radiative decay channels. We show that the radiative decay rate can vary by up to 90% depending on the thickness of the diamond film.
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4
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Gorecki J, Klokkou N, Piper L, Mailis S, Papasimakis N, Apostolopoulos V. High-precision THz-TDS via self-referenced transmission echo method. Appl Opt 2020; 59:6744-6750. [PMID: 32749385 DOI: 10.1364/ao.391103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Terahertz time-domain spectroscopy (TDS) is a powerful characterization technique which allows for the frequency-dependent complex refractive index of a sample to be determined. This is achieved by comparing the time-domain of a pulse transmitted through air to a pulse transmitted through a material sample; however, the requirement for an independent reference scan can introduce errors due to laser fluctuations, mechanical drift, and atmospheric absorption. In this paper, we present a method for determining complex refractive index without an air reference, in which the first pulse transmitted through the sample is compared against the "echo", where the internal reflections delay the transmission of the echo pulse. We present a benchmarking experiment in which the echo reference method is compared to the traditional air method, and show that the echo method is able to reduce variation in real refractive index.
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5
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Pu T, Ou J, Savinov V, Yuan G, Papasimakis N, Zheludev NI. Unlabeled Far-Field Deeply Subwavelength Topological Microscopy (DSTM). Adv Sci (Weinh) 2020; 8:2002886. [PMID: 33437583 PMCID: PMC7788582 DOI: 10.1002/advs.202002886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/28/2020] [Indexed: 06/12/2023]
Abstract
A nonintrusive far-field optical microscopy resolving structures at the nanometer scale would revolutionize biomedicine and nanotechnology but is not yet available. Here, a new type of microscopy is introduced, which reveals the fine structure of an object through its far-field scattering pattern under illumination with light containing deeply subwavelength singularity features. The object is reconstructed by a neural network trained on a large number of scattering events. In numerical experiments on imaging of a dimer, resolving powers better than λ/200, i.e., two orders of magnitude beyond the conventional "diffraction limit" of λ/2, are demonstrated. It is shown that imaging is tolerant to noise and is achievable with low dynamic range light intensity detectors. Proof-of-principle experimental confirmation of DSTM is provided with a training set of small size, yet sufficient to achieve resolution five-fold better than the diffraction limit. In principle, deep learning reconstruction can be extended to objects of random shape and shall be particularly efficient in microscopy of a priori known shapes, such as those found in routine tasks of machine vision, smart manufacturing, and particle counting for life sciences applications.
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Affiliation(s)
- Tanchao Pu
- Optoelectronics Research Centre and Centre for Photonic MetamaterialsUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Jun‐Yu Ou
- Optoelectronics Research Centre and Centre for Photonic MetamaterialsUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Vassili Savinov
- Optoelectronics Research Centre and Centre for Photonic MetamaterialsUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Guanghui Yuan
- Centre for Disruptive Photonic TechnologiesThe Photonics InstituteSchool of Physical and Mathematical SciencesNanyang Technological UniversitySingapore637371Singapore
| | - Nikitas Papasimakis
- Optoelectronics Research Centre and Centre for Photonic MetamaterialsUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Nikolay I. Zheludev
- Optoelectronics Research Centre and Centre for Photonic MetamaterialsUniversity of SouthamptonSouthamptonSO17 1BJUK
- Centre for Disruptive Photonic TechnologiesThe Photonics InstituteSchool of Physical and Mathematical SciencesNanyang Technological UniversitySingapore637371Singapore
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6
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Abstract
We demonstrate experimentally nonvolatile, all-optical control of graphene's charge transport properties by virtue of an Fe:LiNbO3 photoconductive substrate. The substrate can register and sustain photoinduced charge distributions which modify locally the electrostatic environment of the graphene monolayer and allow spatial control of graphene resistivity. We present light-induced changes of graphene sheet resistivity as high as ∼370 Ω/sq (∼2.6-fold increase) under spatially nonuniform light illumination. The light-induced modifications in the sheet resistivity are stable at room temperature but can be reversed by uniform illumination or thermal annealing (100 °C for 4 h), thus restoring graphene's electrical properties to their initial, preillumination values. The process can be subsequently repeated by further spatially nonuniform illumination.
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Affiliation(s)
- Jon Gorecki
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
| | | | - Jun-Yu Ou
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
| | - Sakellaris Mailis
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
| | - Nikitas Papasimakis
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
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7
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Jenkins SD, Ruostekoski J, Papasimakis N, Savo S, Zheludev NI. Many-Body Subradiant Excitations in Metamaterial Arrays: Experiment and Theory. Phys Rev Lett 2017; 119:053901. [PMID: 28949761 DOI: 10.1103/physrevlett.119.053901] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Indexed: 06/07/2023]
Abstract
Subradiant excitations, originally predicted by Dicke, have posed a long-standing challenge in physics owing to their weak radiative coupling to environment. Here we engineer massive coherently driven classical subradiance in planar metamaterial arrays as a spatially extended eigenmode comprising over 1000 metamolecules. By comparing the near- and far-field response in large-scale numerical simulations with those in experimental observations we identify strong evidence for classically correlated multimetamolecule subradiant states that dominate the total excitation energy. We show that similar spatially extended many-body subradiance can also exist in plasmonic metamaterial arrays at optical frequencies.
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Affiliation(s)
- Stewart D Jenkins
- Mathematical Sciences and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Janne Ruostekoski
- Mathematical Sciences and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Nikitas Papasimakis
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Salvatore Savo
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
- TetraScience Inc., 114 Western Ave, Boston, Massachusetts 02134, USA
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore 637378, Singapore
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8
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Papasimakis N, Fedotov VA, Savinov V, Raybould TA, Zheludev NI. Electromagnetic toroidal excitations in matter and free space. Nat Mater 2016; 15:263-71. [PMID: 26906961 DOI: 10.1038/nmat4563] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 01/08/2016] [Indexed: 05/20/2023]
Abstract
The toroidal dipole is a localized electromagnetic excitation, distinct from the magnetic and electric dipoles. While the electric dipole can be understood as a pair of opposite charges and the magnetic dipole as a current loop, the toroidal dipole corresponds to currents flowing on the surface of a torus. Toroidal dipoles provide physically significant contributions to the basic characteristics of matter including absorption, dispersion and optical activity. Toroidal excitations also exist in free space as spatially and temporally localized electromagnetic pulses propagating at the speed of light and interacting with matter. We review recent experimental observations of resonant toroidal dipole excitations in metamaterials and the discovery of anapoles, non-radiating charge-current configurations involving toroidal dipoles. While certain fundamental and practical aspects of toroidal electrodynamics remain open for the moment, we envision that exploitation of toroidal excitations can have important implications for the fields of photonics, sensing, energy and information.
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Affiliation(s)
- N Papasimakis
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - V A Fedotov
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - V Savinov
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - T A Raybould
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - N I Zheludev
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
- TPI and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378, Singapore
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9
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Raybould T, Fedotov V, Papasimakis N, Youngs I, Zheludev N. Focused electromagnetic doughnut pulses and their interaction with interfaces and nanostructures. Opt Express 2016; 24:3150-3161. [PMID: 26906979 DOI: 10.1364/oe.24.003150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
"The "focused doughnut", a single-cycle electromagnetic perturbation of toroidal topology with inseparable time and spatial dependencies propagates at the speed of light in vacuum, as was shown by Hellwarth and Nouchi in 1996. While normal incidence reflection and refraction of conventional electromagnetic pulses in isotropic media do not lead to polarization changes, "focused doughnut" pulses undergo complex field transformations owing to the toroidal field structure and the presence of longitudinal components. We also demonstrate that "focused doughnuts" can interact strongly with structured media exciting dominant dynamic toroidal dipoles in spherical dielectric particles."
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10
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Abb M, Wang Y, Papasimakis N, de Groot CH, Muskens OL. Surface-enhanced infrared spectroscopy using metal oxide plasmonic antenna arrays. Nano Lett 2014; 14:346-352. [PMID: 24341902 DOI: 10.1021/nl404115g] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We successfully demonstrate surface-enhanced infrared spectroscopy using arrays of indium tin oxide (ITO) plasmonic nanoantennas. The ITO antennas show a strongly reduced plasmon wavelength, which holds promise for ultracompact antenna arrays and extremely subwavelength metamaterials. The strong plasmon confinement and reduced antenna cross section allows ITO antennas to be integrated at extremely high densities with no loss in performance due to long-range transverse interactions. By further reducing the spacing of antennas in the arrays, we access the regime of plasmonic near field coupling where the response is enhanced for both Au and ITO devices. Ultracompact ITO antennas with high spatial and spectral selectivity in spectroscopic applications offer a viable new platform for infrared plasmonics, which may be combined with other functionalities of these versatile materials in devices.
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Affiliation(s)
- Martina Abb
- Physics and Astronomy, Faculty of Physical Sciences and Engineering, ‡Nano Group, Faculty of Physical Sciences and Engineering, and §Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton , Highfield, Southampton SO17 1BJ, United Kingdom
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11
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Nikolaenko AE, Papasimakis N, Chipouline A, De Angelis F, Di Fabrizio E, Zheludev NI. THz bandwidth optical switching with carbon nanotube metamaterial. Opt Express 2012; 20:6068-79. [PMID: 22418486 DOI: 10.1364/oe.20.006068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We provide the first demonstration of exceptional light-with-light optical switching performance of a carbon nanotube metamaterial - a hybrid nanostructure of a plasmonic metamaterial with semiconducting single-walled carbon nanotubes. A modulation depth of 10% in the near-IR with sub-500 fs response time is achieved with a pump fluence of just 10 μJ/cm², which is an order of magnitude lower than in previously reported artificial nanostructures. The improved switching characteristics of the carbon nanotube metamaterial are defined by an excitonic nonlinearity of carbon nanotubes resonantly enhanced by a concentration of local fields in the metamaterial. Since the spectral position of the excitonic response and metamaterial plasmonic resonance can be adjusted by using carbon nanotubes of different diameter and scaling of the metamaterial design, the giant nonlinear response of the hybrid metamaterial - in principle - can be engineered to cover the entire second and third telecom windows, from O- to U-band.
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Affiliation(s)
- Andrey E Nikolaenko
- Optoelectronics Research Centre & Centre for photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK.
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12
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Zhang J, Ou JY, Papasimakis N, Chen Y, Macdonald KF, Zheludev NI. Continuous metal plasmonic frequency selective surfaces. Opt Express 2011; 19:23279-23285. [PMID: 22109206 DOI: 10.1364/oe.19.023279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In the microwave part of the spectrum, where losses are minimal, metal films regularly patterned (perforated) on the sub-wavelength scale achieve spectral selectivity by balancing the transmission and reflection characteristics of the surface. Here we show for optical frequencies, where joule losses are important, that periodic structuring of a metal film without violation of continuity (i.e. without perforation) is sufficient to achieve substantial modification of reflectivity. By engineering the geometry of the structure imposed on a surface one can dramatically change the perceived color of the metal without employing any form of chemical modification, thin-film coating or diffraction effects. This novel frequency selective effect is underpinned by plasmonic Joule losses in the constituent elements of the patterns (dubbed 'intaglio' and 'bas relief' metamaterials to distinguish indented and raised structures respectively) and is specific to the optical part of the spectrum. It has the advantage of maintaining the integrity of metal surfaces and is well suited to high-throughput fabrication via techniques such as nano-imprint.
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Affiliation(s)
- Jianfa Zhang
- Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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13
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Abstract
Toroidal multipoles are fundamental electromagnetic excitations different from those associated with the familiar charge and magnetic multipoles. They have been held responsible for parity violation in nuclear and particle physics, but direct evidence of their existence in classical electrodynamics has remained elusive. We report on the observation of a resonant electromagnetic response in an artificially engineered medium, or metamaterial, that cannot be attributed to magnetic or charge multipoles and can only be explained by the existence of a toroidal dipole. Our direct experimental evidence of the toroidal response brings attention to the often ignored electromagnetic interactions involving toroidal multipoles, which could be present in naturally occurring systems, especially at the macromolecule level, where toroidal symmetry is ubiquitous.
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14
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Fedotov VA, Papasimakis N, Plum E, Bitzer A, Walther M, Kuo P, Tsai DP, Zheludev NI. Spectral collapse in ensembles of metamolecules. Phys Rev Lett 2010; 104:223901. [PMID: 20867169 DOI: 10.1103/physrevlett.104.223901] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 04/20/2010] [Indexed: 05/27/2023]
Abstract
We report on the first direct experimental demonstration of a collective phenomenon in metamaterials: spectral line collapse with an increasing number of unit cell resonators (metamolecules). This effect, which is crucial for achieving a lasing spaser, a coherent source of optical radiation fuelled by coherent plasmonic oscillations in metamaterials, is linked to the suppression of radiation losses in periodic arrays. We experimentally demonstrate spectral line collapse at microwave, terahertz and optical frequencies.
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Affiliation(s)
- V A Fedotov
- Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom.
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15
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Nikolaenko AE, De Angelis F, Boden SA, Papasimakis N, Ashburn P, Di Fabrizio E, Zheludev NI. Carbon nanotubes in a photonic metamaterial. Phys Rev Lett 2010; 104:153902. [PMID: 20481991 DOI: 10.1103/physrevlett.104.153902] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/09/2010] [Indexed: 05/23/2023]
Abstract
Hybridization of single-walled carbon nanotubes with plasmonic metamaterials leads to photonic media with an exceptionally strong ultrafast nonlinearity. This behavior is underpinned by strong coupling of the nanotube excitonic response to the weakly radiating Fano-type resonant plasmonic modes that can be tailored by metamaterial design.
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Affiliation(s)
- Andrey E Nikolaenko
- Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, United Kingdom
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16
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Papasimakis N, Luo Z, Shen ZX, De Angelis F, Di Fabrizio E, Nikolaenko AE, Zheludev NI. Graphene in a photonic metamaterial. Opt Express 2010; 18:8353-8359. [PMID: 20588680 DOI: 10.1364/oe.18.008353] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate a photonic metamaterial that shows extraordinary sensitivity to the presence of a single atomic layer of graphene on its surface. Metamaterial's optical transmission increases multi-fold at the resonance frequency linked to the Fano-type plasmonic mode supported by the periodic metallic nanostructure. The experiments were performed with chemical vapor deposited (CVD) graphene covering a number of size-scaled metamaterial samples with plasmonic modes at different frequencies ranging from 167 to 187 Thz.
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Affiliation(s)
- Nikitas Papasimakis
- Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, United Kingdom
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17
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18
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Papasimakis N, Fedotov VA, Marinov K, Zheludev NI. Gyrotropy of a metamolecule: wire on a torus. Phys Rev Lett 2009; 103:093901. [PMID: 19792797 DOI: 10.1103/physrevlett.103.093901] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 07/29/2009] [Indexed: 05/10/2023]
Abstract
Sharing topology with numerous organic molecules, a wire helix bend into a torus gives a curious object with a gyrotropic behavior which is far from obvious. While a continuous constant current in opposite sections of the torus would create mutually cancelling contributions to its gyrotropic response, an array of tori can show strong circular dichroism linked to the excitation of standing current waves. Here we present the experimental study of optical activity in a chiral toroidal metamaterial and discuss its response in terms of multipole moments, including the elusive toroidal moment.
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Affiliation(s)
- N Papasimakis
- Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom.
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19
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Papasimakis N, Fedotov VA, Zheludev NI, Prosvirnin SL. Metamaterial analog of electromagnetically induced transparency. Phys Rev Lett 2008; 101:253903. [PMID: 19113710 DOI: 10.1103/physrevlett.101.253903] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2008] [Revised: 11/12/2008] [Indexed: 05/27/2023]
Abstract
We demonstrate a classical analog of electromagnetically induced transparency in a planar metamaterial. We show that pulses propagating through such metamaterials experience considerable delay. The thickness of the structure along the direction of wave propagation is much smaller than the wavelength, which allows successive stacking of multiple metamaterial slabs leading to increased transmission and bandwidth.
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Affiliation(s)
- N Papasimakis
- Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom.
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20
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Fedotov VA, Rose M, Prosvirnin SL, Papasimakis N, Zheludev NI. Sharp trapped-mode resonances in planar metamaterials with a broken structural symmetry. Phys Rev Lett 2007; 99:147401. [PMID: 17930720 DOI: 10.1103/physrevlett.99.147401] [Citation(s) in RCA: 299] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Indexed: 05/04/2023]
Abstract
We report that a resonance response with a very high quality factor can be achieved in a planar metamaterial by introducing symmetry breaking in the shape of its structural elements, which enables excitation of trapped modes, i.e., modes that are weakly coupled to free space.
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Affiliation(s)
- V A Fedotov
- Optoelectronics Research Centre, University of Southampton, UK
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