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4 páginas, 3 figuras.-- PACS numbers: 41.20.Jb, 42.25.Fx, 42.79.Ag.-- et al. ; We investigate band formation in one-dimensional periodic arrays of rectangular holes which have a nanoscale width but a length of 100 μm. These holes are tailored to work as resonators in the terahertz frequency regime. We study the evolution of the electromagnetic response with the period of the array, showing that this dependence is not monotonic due to both the oscillating behavior of the coupling between holes and its long-range character. ; The experimental work was supported by the Korea Science and Engineering Foundation (KOSEF) (SRC, No. R11-2008-095-01000-0), the Korea Research Foundation (KRF), KICOS (GRL, K20815000003), Hi Seoul Science/Humanities grant funded by the Korea government (MEST) (No. 2009-0071309), the Seoul R&BD Program (10543), and Seoul Scholarship Foundation. The theory work was funded by the Spanish Ministry of Science and Innovation under Projects No. MAT2008- 06609-C02, No. CSD2007-046-NanoLight.es, and by Grant No. RyC-2009-05489. ; Peer reviewed

PACS nrs.: 73.63.Fg, 72.10.Fk, 73.23.-b.-- arXiv: 0801.2732 ; A combination of ab initio simulations and linear-scaling Green's functions techniques is used to analyze the transport properties of long (up to 1 µm) carbon nanotubes with realistic disorder. The energetics and the influence of single defects (monovacancies and divacancies) on the electronic and transport properties of single-walled armchair carbon nanotubes are analyzed as a function of the tube diameter by means of the local orbital first-principles Fireball code. Efficient O(N) Green's functions techniques framed within the Landauer–Büttiker formalism allow a statistical study of the nanotube conductance averaged over a large sample of defected tubes and thus extraction of the nanotube localization length. The cases of zero and room temperature are both addressed. ; This work was partially supported by Spanish MCyT under contracts MAT2004-01271, MAT2005-01298, MAT2002-01534 and NAN2004-09183-C10, and by Comunidad de Madrid under contract S0505/MAT-0303 and the European Community IST-2001-38052 and NMP4-CT-2004-500198 grants. AR acknowledges support by the European Community Network of Excellence Nanoquanta (NMP4-CT-2004-500198), SANES (NMP4-CT-2006-017310), DNANANODEVICES (IST-2006-029192), NANO-ERA-Chemistry projects, Spanish MEC (FIS2007-65702-C02-01), Basque Country University (SGIker ARINA) and Basque Country Government (Grupos Consolidados 2007). ; Peer reviewed

We present an ab initio study of the anisotropy and atomic relaxation effects on the optical properties of nanoparticle dimers. Special emphasis is placed on the hybridization process of localized surface plasmons, plasmon-mediated photoinduced currents, and electric-field enhancement in the dimer junction. We show that there is a critical range of separations between the clusters (0.1–0.5 nm) in which the detailed atomic structure in the junction and the relative orientation of the nanoparticles have to be considered to obtain quantitative predictions for realistic nanoplasmonic devices. It is worth noting that this regime is characterized by the emergence of electron tunneling as a response to the driven electromagnetic field. The orientation of the particles not only modifies the attainable electric field enhancement but can lead to qualitative changes in the optical absorption spectrum of the system. ; We thankfully acknowledge financial support by the European Research Council (ERC-2010-AdG Proposal No. 267374 and ERC-2011-AdG Proposal No. 290891), the Spanish Government (Grants MAT2011-28581-C02-01, FIS2013-46159-C3-1-P, and MAT2014-53432-C5-5-R), and the Basque Country Government (Grupos Consolidados IT-578-13). ; Peer Reviewed

Light-matter interaction in plasmonic nanostructures is often treated within the realm of classical optics. However, recent experimental findings show the need to go beyond the classical models to explain and predict the plasmonic response at the nanoscale. A prototypical system is a nanoparticle dimer, extensively studied using both classical and quantum prescriptions. However, only very recently, fully ab initio time-dependent density functional theory (TDDFT) calculations of the optical response of these dimers have been carried out. Here, we review the recent work on the impact of the atomic structure on the optical properties of such systems. We show that TDDFT can be an invaluable tool to simulate the time evolution of plasmonic modes, providing fundamental understanding into the underlying microscopical mechanisms. ; We thankfully acknowledge the financial support by the European Research Council (ERC-2010-AdG Proposal No. 267374 and ERC-2011-AdG Proposal No. 290891), the Spanish Government (grants MAT2011-28581-C02-01, FIS2013-46159-C3-1-P, and MAT2014-53432-C5-5-R), the Basque Country Government (Grupos Consolidados IT-578-13), and COST Action MP1306 (EUSpec)]. PGG, JF, and FJGV acknowledge financial support from the Spanish Ministry of Economy and Competitiveness, through the "María de Maeztu" Programme for Units of Excellence in R&D (MDM-2014-0377). ; Peer reviewed

Semiclassical nonlocal optics based on the hydrodynamic description of conduction electrons might be an adequate tool to study complex phenomena in the emerging field of nanoplasmonics. With the aim of confirming this idea, we obtain the local and nonlocal optical absorption spectra in a model nanoplasmonic device in which there are spatial gaps between the components at nanometric and subnanometric scales. After a comparison against time-dependent density functional calculations, we conclude that hydrodynamic nonlocal optics provides absorption spectra exhibiting qualitative agreement but not quantitative accuracy. This lack of accuracy, which is manifest even in the limit where induced electric currents are not established between the constituents of the device, is mainly due to the poor description of induced electron densities. ; We thankfully acknowledge the financial support by the European Research Council (ERC-2010-AdG Proposal No. 267374 and ERC-2011-AdG Proposal No. 290891), the European Commission (CRONOS project 280879-2), the Spanish Government (grants FIS2010-21282-C01-01, FIS2010-21282-C02-02, FIS2011-65702-C02-01, PIB2010US-00652, and MAT2011-28581-C02-01), and the Basque Country Government (Grupos Consolidados IT-319-07). ; Peer Reviewed

We analyze the properties of strongly coupled excitons and photons in systems made of semiconducting two-dimensional transition-metal dichalcogenides embedded in optical cavities. Through a detailed microscopic analysis of the coupling, we unveil novel, highly tunable features of the spectrum that result in polariton splitting and a breaking of light-matter selection rules. The dynamics of the composite polaritons is influenced by the Berry phase arising both from their constituents and from the confinement-enhanced coupling. We find that light-matter coupling emerges as a mechanism that enhances the Berry phase of polaritons well beyond that of its elementary constituents, paving the way to achieve a polariton anomalous Hall effect. ; A. G.-R., L. M.-M., and F. G. acknowledge the European Commission under the Graphene Flagship, Contract No. CNECTICT-604391. L. C. and F. G. acknowledge funding from the European Union's Seventh Framework Program (FP7/2007-2013) through the ERC Advanced Grant NOVGRAPHENE (Grant Award No. 290846), and L. C. acknowledges the Comunidad deMadrid through Grant No. MAD2D-CM, S2013/MIT-3007. L. M.-M. and F. J. G.-V. acknowledge financial support by the Spanish MINECO under Contract No. MAT2014-53432-C5. ; Peer reviewed

We present here a theoretical analysis that demonstrates that the far-field radiative heat transfer between objects with dimensions smaller than the thermal wavelength can overcome the Planckian limit by orders of magnitude. To guide the search for super-Planckian far-field radiative heat transfer, we make use of the theory of fluctuational electrodynamics and derive a relation between the far-field radiative heat transfer and the directional absorption efficiency of the objects involved. Guided by this relation, and making use of state-of-the-art numerical simulations, we show that the far-field radiative heat transfer between highly anisotropic objects can largely overcome the black-body limit when some of their dimensions are smaller than the thermal wavelength. In particular, we illustrate this phenomenon in the case of suspended pads made of polar dielectrics like SiN or SiO2. These structures are widely used to measure the thermal transport through nanowires and low-dimensional systems and can be employed to test our predictions. Our work illustrates the dramatic failure of the classical theory to predict the far-field radiative heat transfer between micro- and nanodevices ; We acknowledge funding from the Spanish MINECO (FIS2015-64951-R, MAT2014-53432- C5-5-R, FIS2014-53488-P, FIS2017-84057-P), the Comunidad de Madrid (S2013/MIT-2740), the European Union Seventh Framework Programme (FP7-PEOPLE-2013-CIG- 630996, FP7-PEOPLE-2013-CIG-618229), and the European Research Council (ERC-2011-AdG-290981 and ERC-2016- STG-714870). V.F.-H. acknowledges support from "la Caixa" Foundation and J.C.C. thanks the DFG and SFB767 for sponsoring his stay at the University of Konstanz as Mercator Fellow

This article is available under the terms of the Creative Commons Attribution 3.0 License. ; Here, we introduce the concept of magnetic localized surface plasmons (LSPs), magnetic dipole modes that are supported by cylindrical metal structures corrugated by very long, curved grooves. The resonance wavelength is dictated by the length of the grooves, allowing us to tune it to values much larger than the size of the particle. Moreover, magnetic LSPs also exist for extremely thin metal disks and, therefore, they could be used to devise metasurfaces with magnetic functionalities. Experimental evidence of the existence of these magnetic LSPs in the microwave regime is also presented, although the concept is very general and could be applied to terahertz or infrared frequencies. ; This work was supported in part by the European Research Council (ERC-2011-AdG proposal No. 290981) and the Spanish government (Grants No. CSD2007-0046- Nanolight.es and No. MAT2011-28581-C02). We also acknowledge financial support by the National Science Foundation of China (Grants No. 60990320, No. 60990321, No. 60990324, No. 61171024, No. 61171026, and No. 61138001), by the National High Tech (863) Projects (No. 2012AA030402 and No. 2011AA010202), and by the 111 Project (No. 111-2-05). ; Peer Reviewed