1
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Goncharenko AV, Silkin VM, Chang YC. Nonlinearity vs nonlocality with emphasis on bandwidth broadening in semiconductor-based 1d metamaterials. Opt Express 2024; 32:12551-12568. [PMID: 38571075 DOI: 10.1364/oe.512215] [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: 11/14/2023] [Accepted: 02/06/2024] [Indexed: 04/05/2024]
Abstract
The physics of nonlinear optical materials is incredibly versatile, with the design of novel materials and structures offering numerous degrees of freedom. Nevertheless, weak inherent nonlinearity of conventional optical materials continues to hinder the progress of a number of important applications. In this study, we delve into the realm of broadband enhancement of nonlinearity within one-dimensional (1d) plasmonic metamaterials, exploring its intricate connection with nonlocality. Specifically, we introduce a phenomenological framework for quantifying the effective third-order nonlinear susceptibility of 1d multiphase plasmonic nanostructures, utilizing heavily doped semiconductors, and subsequently applying this approach using realistic material parameters. Both direct and inverse problems of nonlinearity enhancement have been addressed. Our findings demonstrate a remarkable capability to significantly augment the third-order nonlinear susceptibility across a defined frequency range, while concurrently gauging the impact of nonlocality on this enhancement.
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2
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Ushanov VI, Eremeev SV, Silkin VM, Chaldyshev VV. Unveiling Influence of Dielectric Losses on the Localized Surface Plasmon Resonance in (Al,Ga)As:Sb Metamaterials. Nanomaterials (Basel) 2024; 14:167. [PMID: 38251132 DOI: 10.3390/nano14020167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/22/2023] [Accepted: 01/09/2024] [Indexed: 01/23/2024]
Abstract
We perform numerical modeling of the optical absorption spectra of metamaterials composed of systems of semimetal antimony nanoparticles embedded into AlxGa1-xAs semiconductor matrices. We reveal a localized surface plasmon resonance (LSPR) in these metamaterials, which results in a strong optical extinction band below, near, or above the direct band gap of the semiconductor matrices, depending on the chemical composition of the solid solutions. We elucidate the role of dielectric losses in AlxGa1-xAs, which impact the LSPR and cause non-plasmonic optical absorption. It appears that even a dilute system of plasmonic Sb nanoinclusions can substantially change the optical absorption spectra of the medium.
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Affiliation(s)
- Vitalii I Ushanov
- Ioffe Institute, 26 Politekhnicheskaya Str., 194021 Saint Petersburg, Russia
| | - Sergey V Eremeev
- Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences, 634055 Tomsk, Russia
| | - Vyacheslav M Silkin
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, E-20080 San Sebastián, Spain
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, E-20018 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, E-48009 Bilbao, Spain
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3
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Ushanov VI, Eremeev SV, Silkin VM, Chaldyshev VV. Plasmon Resonance in a System of Bi Nanoparticles Embedded into (Al,Ga)As Matrix. Nanomaterials (Basel) 2024; 14:109. [PMID: 38202564 PMCID: PMC10780982 DOI: 10.3390/nano14010109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/25/2023] [Accepted: 12/29/2023] [Indexed: 01/12/2024]
Abstract
We reveal the feasibility of the localized surface plasmon resonance in a system of Bi nanoparticles embedded into an AlxGa1-xAs semiconductor matrix. With an ab initio determined dielectric function for bismuth and well-known dielectric properties of AlxGa1-xAs solid solution, we performed calculations of the optical extinction spectra for such metamaterial using Mie's theory. The calculations demonstrate a strong band of the optical extinction using the localized surface plasmons near a photon energy of 2.5 eV. For the semiconducting matrices with a high aluminum content x>0.7, the extinction by plasmonic nanoparticles plays the dominant role in the optical properties of the medium near the resonance photon energy.
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Affiliation(s)
- Vitalii I. Ushanov
- Ioffe Institute, 26 Politekhnicheskaya Str., 194021 Saint Petersburg, Russia;
| | - Sergey V. Eremeev
- Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences, 634055 Tomsk, Russia;
- Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Vyacheslav M. Silkin
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, E-20080 San Sebastián, Basque Country, Spain
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, E-20018 San Sebastián, Basque Country, Spain
- Ikerbasque, Basque Foundation for Science, E-48011 Bilbao, Basque Country, Spain
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4
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Koroteev YM, Silkin IV, Silkin VM, Chulkov EV. Quantum-Size Effects in Ultra-Thin Gold Films on Pt(111) Surface. Materials (Basel) 2023; 17:63. [PMID: 38203917 PMCID: PMC10779727 DOI: 10.3390/ma17010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024]
Abstract
We calculate, within the density-functional theory, the atomic and electronic structure of the clean Pt(111) and Au(111) surfaces and the nML-Au/Pt(111) systems with n varying from one to three. The effect of the spin-orbital interaction was taken into account. Several new electronic states with strong localization in the surface region were found and discussed in the case of clean surfaces. The Au adlayers introduce numerous quantum well states in the energy regions corresponding to the projected bulk band continuum of Au(111). Moreover, the presence of states resembling the true Au(111) surface states can be detected at n = 2 and 3. The Au/Pd interface states are found as well. In nML-Au/Pt(111), the calculated work function presents a small variation with a variation of the number of the Au atomic layer. Nevertheless, the effect is significantly smaller in comparison to the s-p metals.
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Affiliation(s)
- Yury M. Koroteev
- Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences, 634055 Tomsk, Russia
- Laboratory of Electronic and Spin Structure of Nanosystems, Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - Igor V. Silkin
- Faculty of Physics, Tomsk State University, 634050 Tomsk, Russia
| | - Vyacheslav M. Silkin
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, 20080 San Sebastián, Spain
- Donostia International Physics Center (DIPC), P. Manuel Lardizabal 4, 20018 San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, Pl. Euskadi 5, 48009 Bilbao, Spain
| | - Evgueni V. Chulkov
- Laboratory of Electronic and Spin Structure of Nanosystems, Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, 20080 San Sebastián, Spain
- Donostia International Physics Center (DIPC), P. Manuel Lardizabal 4, 20018 San Sebastián, Spain
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, P. Manuel Lardizabal 5, 20018 San Sebastián, Spain
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5
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Baumberg JJ, Esteban R, Hu S, Muniain U, Silkin IV, Aizpurua J, Silkin VM. Quantum Plasmonics in Sub-Atom-Thick Optical Slots. Nano Lett 2023; 23:10696-10702. [PMID: 38029409 PMCID: PMC10722603 DOI: 10.1021/acs.nanolett.3c02537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 12/01/2023]
Abstract
We show using time-dependent density functional theory (TDDFT) that light can be confined into slot waveguide modes residing between individual atomic layers of coinage metals, such as gold. As the top atomic monolayer lifts a few Å off the underlying bulk Au (111), ab initio electronic structure calculations show that for gaps >1.5 Å, visible light squeezes inside the empty slot underneath, giving optical field distributions 2 Å thick, less than the atomic diameter. Paradoxically classical electromagnetic models are also able to reproduce the resulting dispersion for these subatomic slot modes, where light reaches in-plane wavevectors ∼2 nm-1 and slows to <10-2c. We explain the success of these classical dispersion models for gaps ≥1.5 Å due to a quantum-well state forming in the lifted monolayer in the vicinity of the Fermi level. This extreme trapping of light may explain transient "flare" emission from plasmonic cavities where Raman scattering of metal electrons is greatly enhanced when subatomic slot confinement occurs. Such atomic restructuring of Au under illumination is relevant to many fields, from photocatalysis and molecular electronics to plasmonics and quantum optics.
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Affiliation(s)
- Jeremy J. Baumberg
- Nanophotonics
Centre, Cavendish Laboratory, University
of Cambridge, Cambridge CB3 0HE, United
Kingdom
| | - Ruben Esteban
- Donostia
International Physics Center, P. de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Basque Country, Spain
- Centro
de Física de Materiales, Centro Mixto
CSIC-UPV/EHU, P. de Manuel
Lardizabal, 5, 20018 San Sebastián/Donostia, Basque Country, Spain
| | - Shu Hu
- Nanophotonics
Centre, Cavendish Laboratory, University
of Cambridge, Cambridge CB3 0HE, United
Kingdom
| | - Unai Muniain
- Donostia
International Physics Center, P. de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Basque Country, Spain
| | | | - Javier Aizpurua
- Donostia
International Physics Center, P. de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Basque Country, Spain
- Centro
de Física de Materiales, Centro Mixto
CSIC-UPV/EHU, P. de Manuel
Lardizabal, 5, 20018 San Sebastián/Donostia, Basque Country, Spain
| | - Vyacheslav M. Silkin
- Donostia
International Physics Center, P. de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
- Departamento
de Polímeros y Materiales Avanzados: Física,
Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, 20080 San Sebastián/Donostia, Basque Country, Spain
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6
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Silkin VM, Drechsler SL, Efremov DV. Unusual Low-Energy Collective Charge Excitations in High- Tc Cuprate Superconductors. J Phys Chem Lett 2023; 14:8060-8068. [PMID: 37655950 PMCID: PMC10510710 DOI: 10.1021/acs.jpclett.3c01871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 08/14/2023] [Indexed: 09/02/2023]
Abstract
Despite decades of intensive experimental and theoretical efforts, the physics of cuprate high-temperature superconductors in general, and, in particular, their normal state, is still under debate. Here, we report our investigation of low-energy charge excitations in the normal state. We find that the peculiarities of the electronic band structure at low energies have a profound impact on the nature of the intraband collective modes. It gives rise to a new kind of mode with huge intensity and non-Lorentzian spectral function in addition to well-known collective excitations like conventional plasmons and spin fluctuation. We predict two such modes with maximal spectral weight in the nodal and antinodal directions. Additionally, we found a long-living quasi-one-dimensional plasmon becoming an intense soft mode over an extended momentum range along the antinodal direction. These modes might explain some of the resonant inelastic X-ray scattering spectroscopy data.
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Affiliation(s)
- Vyacheslav M. Silkin
- Donostia
International Physics Center (DIPC), 20018 San Sebastián/Donostia, Basque Country, Spain
- Departamento
de Polímeros y Materiales Avanzados: Física,
Química y Tecnología, Facultad de Ciencias
Químicas, Universidad del País
Vasco UPV/EHU, 20080 San Sebastián/Donostia, Basque Country, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Stefan-Ludwig Drechsler
- Leibniz
Institute for Solid State and Materials Research IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Dmitry V. Efremov
- Leibniz
Institute for Solid State and Materials Research IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
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7
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Goncharenko AV, Silkin VM. Multipole Excitations and Nonlocality in 1d Plasmonic Nanostructures. Nanomaterials (Basel) 2023; 13:1395. [PMID: 37110980 PMCID: PMC10144308 DOI: 10.3390/nano13081395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 06/19/2023]
Abstract
Efficient simulation methods for taking nonlocal effects in nanostructures into account have been developed, but they are usually computationally expensive or provide little insight into underlying physics. A multipolar expansion approach, among others, holds promise to properly describe electromagnetic interactions in complex nanosystems. Conventionally, the electric dipole dominates in plasmonic nanostructures, while higher order multipoles, especially the magnetic dipole, electric quadrupole, magnetic quadrupole, and electric octopole, can be responsible for many optical phenomena. The higher order multipoles not only result in specific optical resonances, but they are also involved in the cross-multipole coupling, thus giving rise to new effects. In this work, we introduce a simple yet accurate simulation modeling technique, based on the transfer-matrix method, to compute higher-order nonlocal corrections to the effective permittivity of 1d plasmonic periodic nanostructures. In particular, we show how to specify the material parameters and the arrangement of the nanolayers in order to maximize or minimize various nonlocal corrections. The obtained results provide a framework for guiding and interpreting experiments, as well as for designing metamaterials with desired dielectric and optical properties.
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Affiliation(s)
- Anatoliy V. Goncharenko
- V.E. Lashkaryov Institute of Semiconductor Physics, Nauky Ave. 41, 03028 Kyiv, Ukraine
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastian, Spain
| | - Vyacheslav M. Silkin
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastian, Spain
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV/EHU), 20080 San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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8
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Silkin VM, Eremeev SV, Ushanov VI, Chaldyshev VV. Localized Surface Plasmon Resonance in Metamaterials Composed of As 1-zSb z Semimetal Nanoparticles in Al xGa 1-xAs 1-ySb y Semiconductor Matrix. Nanomaterials (Basel) 2023; 13:1355. [PMID: 37110940 PMCID: PMC10146142 DOI: 10.3390/nano13081355] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/11/2023] [Accepted: 04/11/2023] [Indexed: 06/19/2023]
Abstract
We analyze the possibility to realize a localized surface plasmon resonance in metamaterials composed of As1-zSbz nanoparticles embedded in an AlxGa1-xAs1-ySby semiconductor matrix. To this end, we perform ab initio calculations of the dielectric function of the As1-zSbz materials. Changing the chemical composition z, we trace the evolution of the band structure, dielectric function, and loss function. In terms of the Mie theory, we calculate the polarizability and optical extinction of a system of As1-zSbz nanoparticles in an AlxGa1-xAs1-ySby environment. We show a possibility to provide localized surface plasmon resonance near the band gap of the AlxGa1-xAs1-ySby semiconductor matrix by a built-in system of As1-zSbz nanoparticles strongly enriched by Sb. The results of our calculations are supported by available experimental data.
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Affiliation(s)
- Vyacheslav M. Silkin
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, E-20080 San Sebastián, Spain
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, E-20018 San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, E-48011 Bilbao, Spain
| | - Sergey V. Eremeev
- Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences, 634055 Tomsk, Russia
| | - Vitalii I. Ushanov
- Ioffe Institute, 26 Politekhnicheskaya Str., 194021 Saint Petersburg, Russia;
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9
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Koroteev YM, Silkin IV, Chernov IP, Chulkov EV, Silkin VM. Acoustic Plasmons in Nickel and Its Modification upon Hydrogen Uptake. Nanomaterials (Basel) 2022; 13:141. [PMID: 36616051 PMCID: PMC9823890 DOI: 10.3390/nano13010141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
In this work, we study, in the framework of the ab initio linear-response time-dependent density functional theory, the low-energy collective electronic excitations with characteristic sound-like dispersion, called acoustic plasmons, in bulk ferromagnetic nickel. Since the respective spatial oscillations in slow and fast charge systems involve states with different spins, excitation of such plasmons in nickel should result in the spatial variations in the spin structure as well. We extend our study to NiHx with different hydrogen concentrations x. We vary the hydrogen concentration and trace variations in the acoustic plasmons properties. Finally, at x=1 the acoustic modes disappear in paramagnetic NiH. The explanation of such evolution is based on the changes in the population of different energy bands with hydrogen content variation.
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Affiliation(s)
- Yury M. Koroteev
- Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences, 634050 Tomsk, Russia
| | - Igor V. Silkin
- Faculty of Physics, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia
| | - Ivan P. Chernov
- Engineering School of Nuclear Technology, Tomsk Polytechnical University, Lenin Ave. 30, 634050 Tomsk, Russia
| | - Evgueni V. Chulkov
- Laboratory of Electronic and Spin Structure of Nanosystems, St. Petersburg State University, 198504 St. Petersburg, Russia
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, E-20080 San Sebastián, Spain
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, E-20018 San Sebastián, Spain
- Centro de Fisica de Materiales, Centro Mixto CSIC-UPV/EHU, P. de Manuel Lardizabal, 5, E-20018 San Sebastián, Spain
| | - Vyacheslav M. Silkin
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco (UPV-EHU), Apdo. 1072, E-20080 San Sebastián, Spain
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, E-20018 San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, E-48011 Bilbao, Spain
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10
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Lin Z, Wang C, Balassis A, Echeverry JP, Vasenko AS, Silkin VM, Chulkov EV, Shi Y, Zhang J, Guo J, Zhu X. Dramatic Plasmon Response to the Charge-Density-Wave Gap Development in 1T-TiSe_{2}. Phys Rev Lett 2022; 129:187601. [PMID: 36374677 DOI: 10.1103/physrevlett.129.187601] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 04/20/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
1T-TiSe_{2} is one of the most studied charge density wave (CDW) systems, not only because of its peculiar properties related to the CDW transition, but also due to its status as a promising candidate of exciton insulator signaled by the proposed plasmon softening at the CDW wave vector. Using high-resolution electron energy loss spectroscopy, we report a systematic study of the temperature-dependent plasmon behaviors of 1T-TiSe_{2}. We unambiguously resolve the plasmon from phonon modes, revealing the existence of Landau damping to the plasmon at finite momentums, which does not support the plasmon softening picture for exciton condensation. Moreover, we discover that the plasmon lifetime at zero momentum responds dramatically to the band gap evolution associated with the CDW transition. The interband transitions near the Fermi energy in the normal phase are demonstrated to serve as a strong damping channel of plasmons, while such a channel in the CDW phase is suppressed due to the CDW gap opening, which results in the dramatic tunability of the plasmon in semimetals or small-gap semiconductors.
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Affiliation(s)
- Zijian Lin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cuixiang Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - A Balassis
- Department of Physics and Engineering Physics, Fordham University, 441 East Fordham Road, Bronx, New York 10458, USA
| | - J P Echeverry
- Universidad de Ibagué Carrera 22 Calle 67 B, Av. Ambalá Ibagué Tolima 730007, Colombia
| | - A S Vasenko
- HSE University, 101000 Moscow, Russia
- I. E. Tamm Department of Theoretical Physics, P. N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
| | - V M Silkin
- Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Basque Country, Spain
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, Apartado 1072, 20080 San Sebastián/Donostia, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - E V Chulkov
- HSE University, 101000 Moscow, Russia
- Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Basque Country, Spain
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, Apartado 1072, 20080 San Sebastián/Donostia, Basque Country, Spain
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Jiandi Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiandong Guo
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Xuetao Zhu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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11
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Muniain U, Silkin VM. Impact of the energy dispersion anisotropy on the plasmonic structure in a two-dimensional electron system. Phys Chem Chem Phys 2022; 24:17885-17894. [PMID: 35852308 DOI: 10.1039/d2cp02050e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of the band structure anisotropy (triangular, square, and hexagonal wrapping) on the electronic collective excitations (plasmons) in a two-dimensional electron gas (2DEG) is studied in the framework of the random-phase approximation. We show that the dynamical dielectric response in these systems strongly depends on the direction of the in-plane momentum transfer q. The effect is so pronounced that it results in a different number of electronic collective excitations in some q regions, both with - and ∼q-like energy dispersions. This finding is in striking contrast to the conventional 2DEG case with isotropic energy band dispersion where only a single plasmon with dispersion can exist. Our prediction of acoustic modes (with the ∼q dispersion) in a one-energy-band electron system expands the previous knowledge that such kind of plasmon can be realized only in two-component systems.
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Affiliation(s)
- Unai Muniain
- Donostia International Physics Center (DIPC), P. de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Basque Country, Spain.
| | - Vyacheslav M Silkin
- Donostia International Physics Center (DIPC), P. de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Basque Country, Spain. .,Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, Apartado 1072, 20080 San Sebastián/Donostia, Basque Country, Spain.,IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
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12
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Martín-Jiménez A, Lauwaet K, Jover Ó, Granados D, Arnau A, Silkin VM, Miranda R, Otero R. Electronic Temperature and Two-Electron Processes in Overbias Plasmonic Emission from Tunnel Junctions. Nano Lett 2021; 21:7086-7092. [PMID: 34152778 DOI: 10.1021/acs.nanolett.1c00951] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The accurate determination of electronic temperatures in metallic nanostructures is essential for many technological applications, like plasmon-enhanced catalysis or lithographic nanofabrication procedures. In this Letter, we demonstrate that the electronic temperature can be accurately measured by the shape of the tunnel electroluminescence emission edge in tunnel plasmonic nanocavities, which follows a universal thermal distribution with the bias voltage as the chemical potential of the photon population. A significant deviation between electronic and lattice temperatures is found below 30 K for tunnel currents larger than 15 nA. This deviation is rationalized as the result of a two-electron process in which the second electron excites plasmon modes with an energy distribution that reflects the higher temperature following the first tunneling event. These results dispel a long-standing controversy on the nature of overbias emission in tunnel junctions and adds a new method for the determination of electronic temperatures and quasiparticle dynamics.
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Affiliation(s)
| | | | - Óscar Jover
- IMDEA Nanoscience, 28049 Madrid, Spain
- Depto. de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | | | - Andrés Arnau
- Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Spain
- Depto. de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Química, Universidad del País Vasco UPV/EHU, Apartado 1072, 20080 San Sebastián/Donostia, Spain
- Centro de Fisica de Materiales CFM/MPC (CSIC-UPV/EHU), Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain
| | - Vyacheslav M Silkin
- Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Spain
- Depto. de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Química, Universidad del País Vasco UPV/EHU, Apartado 1072, 20080 San Sebastián/Donostia, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Rodolfo Miranda
- IMDEA Nanoscience, 28049 Madrid, Spain
- Depto. de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Roberto Otero
- IMDEA Nanoscience, 28049 Madrid, Spain
- Depto. de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
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13
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Benedek G, Bernasconi M, Campi D, Silkin IV, Chernov IP, Silkin VM, Chulkov EV, Echenique PM, Toennies JP, Anemone G, Al Taleb A, Miranda R, Farías D. Evidence for a spin acoustic surface plasmon from inelastic atom scattering. Sci Rep 2021; 11:1506. [PMID: 33452337 PMCID: PMC7810840 DOI: 10.1038/s41598-021-81018-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 10/06/2020] [Accepted: 12/29/2020] [Indexed: 11/09/2022] Open
Abstract
Closed-shell atoms scattered from a metal surface exchange energy and momentum with surface phonons mostly via the interposed surface valence electrons, i.e., via the creation of virtual electron-hole pairs. The latter can then decay into surface phonons via electron-phonon interaction, as well as into acoustic surface plasmons (ASPs). While the first channel is the basis of the current inelastic atom scattering (IAS) surface-phonon spectroscopy, no attempt to observe ASPs with IAS has been made so far. In this study we provide evidence of ASP in Ni(111) with both Ne atom scattering and He atom scattering. While the former measurements confirm and extend so far unexplained data, the latter illustrate the coupling of ASP with phonons inside the surface-projected phonon continuum, leading to a substantial reduction of the ASP velocity and possibly to avoided crossing with the optical surface phonon branches. The analysis is substantiated by a self-consistent calculation of the surface response function to atom collisions and of the first-principle surface-phonon dynamics of Ni(111). It is shown that in Ni(111) ASP originate from the majority-spin Shockley surface state and are therefore collective oscillation of surface electrons with the same spin, i.e. it represents a new kind of collective quasiparticle: a Spin Acoustic Surface Plasmon (SASP).
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Affiliation(s)
- G Benedek
- Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via R. Cozzi 55, 20125, Milan, Italy.,Donostia International Physics Center (DIPC), 20018, San Sebastián/Donostia, Basque Country, Spain
| | - M Bernasconi
- Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via R. Cozzi 55, 20125, Milan, Italy
| | - D Campi
- Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via R. Cozzi 55, 20125, Milan, Italy.,École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - I V Silkin
- Tomsk State University, 634050, Tomsk, Russia
| | - I P Chernov
- Engineering School of Nuclear Technology, Tomsk Polytechnic University, 634050, Tomsk, Russia
| | - V M Silkin
- Donostia International Physics Center (DIPC), 20018, San Sebastián/Donostia, Basque Country, Spain.,Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, 20080, San Sebastián/Donostia, Basque Country, Spain.,IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Basque Country, Spain
| | - E V Chulkov
- Donostia International Physics Center (DIPC), 20018, San Sebastián/Donostia, Basque Country, Spain.,Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, 20080, San Sebastián/Donostia, Basque Country, Spain.,Centro de Fisica de Materiales, Centro Mixto CSIC-UPV/EHU, 20018, San Sebastian/Donostia, Basque Country, Spain.,St. Petersburg State University, 198504, St. Petersburg, Russia
| | - P M Echenique
- Donostia International Physics Center (DIPC), 20018, San Sebastián/Donostia, Basque Country, Spain.,Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, 20080, San Sebastián/Donostia, Basque Country, Spain.,Centro de Fisica de Materiales, Centro Mixto CSIC-UPV/EHU, 20018, San Sebastian/Donostia, Basque Country, Spain
| | - J P Toennies
- Max-Planck-Institut für Dynamik und Selbstorganisation, Bunsenstraße 10, 37073, Göttingen, Germany
| | - G Anemone
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - A Al Taleb
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - R Miranda
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049, Madrid, Spain.,Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - D Farías
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain. .,Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049, Madrid, Spain. .,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049, Madrid, Spain.
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14
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Silkin VM, Chulkov EV, Echenique PM. Collective electronic excitations on the MgB2(0001) surfaces. Advances in Quantum Chemistry 2019. [DOI: 10.1016/bs.aiq.2019.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Siek F, Neb S, Bartz P, Hensen M, Strüber C, Fiechter S, Torrent-Sucarrat M, Silkin VM, Krasovskii EE, Kabachnik NM, Fritzsche S, Muiño RD, Echenique PM, Kazansky AK, Müller N, Pfeiffer W, Heinzmann U. Angular momentum–induced delays in solid-state photoemission enhanced by intra-atomic interactions. Science 2017; 357:1274-1277. [DOI: 10.1126/science.aam9598] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 08/11/2017] [Indexed: 11/02/2022]
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16
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Baldini E, Mann A, Benfatto L, Cappelluti E, Acocella A, Silkin VM, Eremeev SV, Kuzmenko AB, Borroni S, Tan T, Xi XX, Zerbetto F, Merlin R, Carbone F. Real-Time Observation of Phonon-Mediated σ-π Interband Scattering in MgB_{2}. Phys Rev Lett 2017; 119:097002. [PMID: 28949564 DOI: 10.1103/physrevlett.119.097002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Indexed: 06/07/2023]
Abstract
In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene, and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent electronic properties. Here we show that the population of E_{2g} phonons in the multiband superconductor MgB_{2} can be selectively enhanced by femtosecond laser pulses, leading to a transient control of the number of carriers in the σ-electronic subsystem. The nonequilibrium evolution of the material optical constants is followed in the spectral region sensitive to both the a- and c-axis plasma frequencies and modeled theoretically, revealing the details of the σ-π interband scattering mechanism in MgB_{2}.
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Affiliation(s)
- E Baldini
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - A Mann
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - L Benfatto
- Institute for Complex Systems-CNR, and Physics Department, University of Rome "La Sapienza", I-00185 Rome, Italy
| | - E Cappelluti
- Institute for Complex Systems-CNR, and Physics Department, University of Rome "La Sapienza", I-00185 Rome, Italy
| | - A Acocella
- Department of Chemistry "G. Ciamician," Università di Bologna, I-40126 Bologna, Italy
| | - V M Silkin
- Departamento de Física de Materiales, Universidad del País Vasco, 20080 San Sebastián/Donostia, Spain
- Donostia International Physics Center, 20018 San Sebastián/Donostia, Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - S V Eremeev
- Institute of Strength Physics and Materials Science, 634055 Tomsk, Russia
- Tomsk State University, 634050 , Tomsk, Russia
| | - A B Kuzmenko
- Department of Quantum Matter Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - S Borroni
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - T Tan
- Department of Material Science and Engineering, The Pennsylvania State University, Pennsylvania 16802, USA
| | - X X Xi
- Department of Material Science and Engineering, The Pennsylvania State University, Pennsylvania 16802, USA
| | - F Zerbetto
- Department of Chemistry "G. Ciamician," Università di Bologna, I-40126 Bologna, Italy
| | - R Merlin
- Department of Physics, Center for Photonics and Multiscale Nanomaterials, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| | - F Carbone
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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17
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Vasenko AS, Golubov AA, Silkin VM, Chulkov EV. Odd-frequency superconductivity induced in topological insulators with and without hexagonal warping. J Phys Condens Matter 2017; 29:295502. [PMID: 28557795 DOI: 10.1088/1361-648x/aa75c3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We study the effect of the Fermi surface anisotropy on the odd-frequency spin-triplet pairing component of the induced pair potential. We consider a superconductor/ ferromagnetic insulator (S/FI) hybrid structure formed on the 3D topological insulator (TI) surface. In this case three ingredients ensure the possibility of the odd-frequency pairing: (1) the topological surface states, (2) the induced pair potential, and (3) the magnetic moment of a nearby ferromagnetic insulator. We take into account the strong anisotropy of the Dirac point in topological insulators when the chemical potential lies well above the Dirac cone and its constant energy contour has a snowflake shape. Within this model, we propose that the S/FI boundary should be properly aligned with respect to the snowflake constant energy contour to have an odd-frequency symmetry of the corresponding pairing component and to insure the Majorana bound state at the S/FI boundary. For arbitrary orientation of the boundary, the Majorana bound state is absent. This provides a selection rule to the realization of Majorana modes in S/FI hybrid structures, formed on the topological insulator surface.
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Affiliation(s)
- A S Vasenko
- National Research University Higher School of Economics, 101000 Moscow, Russia
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18
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Faraggi MN, Zubizarreta X, Arnau A, Silkin VM. On the stability of the electronic system in transition metal dichalcogenides. J Phys Condens Matter 2016; 28:184004. [PMID: 27057801 DOI: 10.1088/0953-8984/28/18/184004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Based on first-principles calculations, we prove that the origin of charge-density wave formation in metallic layered transition metal dichalcogenides (TMDC) is not due to an electronic effect, like the Fermi surface (FS) nesting, as it had been proposed. In particular, we consider NbSe2, NbS2, TaSe2, and TaS2 as representative examples of 2H-TMDC polytypes. Our main result consists that explicit inclusion of the matrix elements in first-principles calculations of the electron susceptibility [Formula: see text] removes, due to strong momentum dependence of the matrix elements, almost all the information about the FS topologies in the resulting [Formula: see text]. This finding strongly supports an interpretation in which the momentum dependence of the electron-phonon interaction is the only reason why the phenomenon of charge-density waves appears in this class of materials.
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Affiliation(s)
- M N Faraggi
- Donostia International Physics Center (DIPC), P. de Manuel Lardizabal, 4, 20018 San Sebastián, Basque Country, Spain. Instituto de Astronomía y Física del Espacio, Conicet, Buenos Aires, Argentina. École Normale Supérieure, Département de Chimie, Sorbone Université, UPMC Univ. Paris 06, CNRS UMP 8640, Paris, France
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19
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Politano A, Silkin VM, Nechaev IA, Vitiello MS, Viti L, Aliev ZS, Babanly MB, Chiarello G, Echenique PM, Chulkov EV. Interplay of Surface and Dirac Plasmons in Topological Insulators: The Case of Bi_{2}Se_{3}. Phys Rev Lett 2015; 115:216802. [PMID: 26636863 DOI: 10.1103/physrevlett.115.216802] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Indexed: 06/05/2023]
Abstract
We have investigated plasmonic excitations at the surface of Bi_{2}Se_{3}(0001) via high-resolution electron energy loss spectroscopy. For low parallel momentum transfer q_{∥}, the loss spectrum shows a distinctive feature peaked at 104 meV. This mode varies weakly with q_{∥}. The behavior of its intensity as a function of primary energy and scattering angle indicates that it is a surface plasmon. At larger momenta (q_{∥}~0.04 Å^{-1}), an additional peak, attributed to the Dirac plasmon, becomes clearly defined in the loss spectrum. Momentum-resolved loss spectra provide evidence of the mutual interaction between the surface plasmon and the Dirac plasmon of Bi_{2}Se_{3}. The proposed theoretical model accounting for the coexistence of three-dimensional doping electrons and two-dimensional Dirac fermions accurately represents the experimental observations. The results reveal novel routes for engineering plasmonic devices based on topological insulators.
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Affiliation(s)
- A Politano
- Department of Physics, University of Calabria, 87036 Rende (CS), Italy
| | - V M Silkin
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain
- Departamento de Física de Materiales, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - I A Nechaev
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain
- Tomsk State University, 634050 Tomsk, Russian Federation
- Saint Petersburg State University, 198504 Saint Petersburg, Russian Federation
| | - M S Vitiello
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - L Viti
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Z S Aliev
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain
- Institute of Catalysis and Inorganic Chemistry, ANAS, AZ1143 Baku, Azerbaijian
- Institute of Physics, ANAS, AZ1143 Baku, Azerbaijian
| | - M B Babanly
- Institute of Catalysis and Inorganic Chemistry, ANAS, AZ1143 Baku, Azerbaijian
| | - G Chiarello
- Department of Physics, University of Calabria, 87036 Rende (CS), Italy
- CNISM, Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Via della Vasca Navale, 84, 00146 Roma, Italy
| | - P M Echenique
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain
- Departamento de Física de Materiales, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain
- Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain
| | - E V Chulkov
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain
- Departamento de Física de Materiales, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain
- Tomsk State University, 634050 Tomsk, Russian Federation
- Saint Petersburg State University, 198504 Saint Petersburg, Russian Federation
- Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain
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20
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Sessi P, Silkin VM, Nechaev IA, Bathon T, El-Kareh L, Chulkov EV, Echenique PM, Bode M. Direct observation of many-body charge density oscillations in a two-dimensional electron gas. Nat Commun 2015; 6:8691. [PMID: 26498368 DOI: 10.1038/ncomms9691] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 09/22/2015] [Indexed: 12/22/2022] Open
Abstract
Quantum interference is a striking manifestation of one of the basic concepts of quantum mechanics: the particle-wave duality. A spectacular visualization of this effect is the standing wave pattern produced by elastic scattering of surface electrons around defects, which corresponds to a modulation of the electronic local density of states and can be imaged using a scanning tunnelling microscope. To date, quantum-interference measurements were mainly interpreted in terms of interfering electrons or holes of the underlying band-structure description. Here, by imaging energy-dependent standing-wave patterns at noble metal surfaces, we reveal, in addition to the conventional surface-state band, the existence of an 'anomalous' energy band with a well-defined dispersion. Its origin is explained by the presence of a satellite in the structure of the many-body spectral function, which is related to the acoustic surface plasmon. Visualizing the corresponding charge oscillations provides thus direct access to many-body interactions at the atomic scale.
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Affiliation(s)
- Paolo Sessi
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Vyacheslav M Silkin
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain.,Departamento de Física de Materiales, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain.,IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Ilya A Nechaev
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain.,Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain.,Tomsk State University, 634050 Tomsk, Russia.,Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - Thomas Bathon
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Lydia El-Kareh
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Evgueni V Chulkov
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain.,Departamento de Física de Materiales, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain.,Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain.,Tomsk State University, 634050 Tomsk, Russia.,Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - Pedro M Echenique
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain.,Departamento de Física de Materiales, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain.,Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM), Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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21
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Silkin VM, Nazarov VU, Chernov IP, Sklyadneva IY, Chulkov EV. Low-energy dielectric screening in Pd and PdHx systems. J Phys Condens Matter 2015; 27:055501. [PMID: 25604038 DOI: 10.1088/0953-8984/27/5/055501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Modifications in dielectric properties of palladium upon absorption of hydrogen are investigated theoretically in the low-energy (0-2 eV) region. The calculations were performed with full inclusion of the electronic band structure obtained within a self-consistent pseudopotential approach. In particular, we trace the evolution of the acoustic-like plasmon (AP) found previously in clean Pd with increasing hydrogen concentration. It exists in PdHx up to the hydrogen content x corresponding to the complete filling of the 4d Pd-derived energy bands because of the presence of two kinds of carriers at the Fermi surface. At higher H concentration the AP disappears since only one kind of carrier within the sp-like energy band exists at the Fermi level. Additionally, we investigate the spatial distribution inside the crystal of a potential caused by a time-dependent external perturbation and observe drastic modifications in the screening properties in the PdHx systems with energy and with hydrogen concentration.
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Affiliation(s)
- V M Silkin
- Departamento de Física de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Químicas, Universidad del País Vasco, Apdo. 1072, 20080 San Sebastián, Basque Country, Spain. Donostia International Physics Center (DIPC), P. de Manuel Lardizabal, 4, 20018 San Sebastián, Basque Country, Spain. IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain
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22
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Smerieri M, Vattuone L, Savio L, Langer T, Tegenkamp C, Pfnür H, Silkin VM, Rocca M. Anisotropic dispersion and partial localization of acoustic surface plasmons on an atomically stepped surface: Au(788). Phys Rev Lett 2014; 113:186804. [PMID: 25396388 DOI: 10.1103/physrevlett.113.186804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Indexed: 06/04/2023]
Abstract
Understanding acoustic surface plasmons (ASPs) in the presence of nanosized gratings is necessary for the development of future devices that couple light with ASPs. We show here by experiment and theory that two ASPs exist on Au(788), a vicinal surface with an ordered array of monoatomic steps. The ASPs propagate across the steps as long as their wavelength exceeds the terrace width, thereafter becoming localized. Our investigation identifies, for the first time, ASPs coupled with intersubband transitions involving multiple surface-state subbands.
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Affiliation(s)
- M Smerieri
- IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - L Vattuone
- IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 16146 Genova, Italy and Dipartimento di Fisica dell'Universitá di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - L Savio
- IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - T Langer
- Institut für Festkörperphysik, Abteilung Atomare und Molekulare Strukturen, Leibniz Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany
| | - C Tegenkamp
- Institut für Festkörperphysik, Abteilung Atomare und Molekulare Strukturen, Leibniz Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany
| | - H Pfnür
- Institut für Festkörperphysik, Abteilung Atomare und Molekulare Strukturen, Leibniz Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany
| | - V M Silkin
- Departamento de Física de Materiales, Facultad de Ciencias Químicas, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain and Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain and IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - M Rocca
- IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 16146 Genova, Italy and Dipartimento di Fisica dell'Universitá di Genova, Via Dodecaneso 33, 16146 Genova, Italy
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Vattuone L, Smerieri M, Langer T, Tegenkamp C, Pfnür H, Silkin VM, Chulkov EV, Echenique PM, Rocca M. Correlated motion of electrons on the Au(111) surface: anomalous acoustic surface-plasmon dispersion and single-particle excitations. Phys Rev Lett 2013; 110:127405. [PMID: 25166849 DOI: 10.1103/physrevlett.110.127405] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Indexed: 06/03/2023]
Abstract
The linear dispersion of the low-dimensional acoustic surface plasmon (ASP) opens perspectives in energy conversion, transport, and confinement far below optical frequencies. Although the ASP exists in a wide class of materials, ranging from metal surfaces and ultrathin films to graphene and topological insulators, its properties are still largely unexplored. Taking Au(111) as a model system, our combined experimental and theoretical study revealed an intriguing interplay between collective and single particle excitations, causing the ASP associated with the Shockley surface state to be embedded within the intraband transitions without losing its sharp character and linear dispersion.
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Affiliation(s)
- L Vattuone
- Dipartimento di Fisica dell'Universitá di Genova and IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 15146 Genova, Italy
| | - M Smerieri
- Dipartimento di Fisica dell'Universitá di Genova and IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 15146 Genova, Italy
| | - T Langer
- Institut für Festkörperphysik, Abteilung Atomare und Molekulare Strukturen, Leibniz Universität Hannover, Appelstraße 2, D-30167 Hannover, Germany
| | - C Tegenkamp
- Institut für Festkörperphysik, Abteilung Atomare und Molekulare Strukturen, Leibniz Universität Hannover, Appelstraße 2, D-30167 Hannover, Germany
| | - H Pfnür
- Institut für Festkörperphysik, Abteilung Atomare und Molekulare Strukturen, Leibniz Universität Hannover, Appelstraße 2, D-30167 Hannover, Germany
| | - V M Silkin
- Departamento de Física de Materiales, Facultad de Ciencias Químicas, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain and Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain and IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - E V Chulkov
- Departamento de Física de Materiales, Facultad de Ciencias Químicas, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain and Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain and Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain
| | - P M Echenique
- Departamento de Física de Materiales, Facultad de Ciencias Químicas, Universidad del País Vasco, Apartado 1072, 20080 San Sebastián/Donostia, Spain and Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastián/Donostia, Spain and Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Paseo de Manuel Lardizabal 5, 20018 San Sebastián/Donostia, Spain
| | - M Rocca
- Dipartimento di Fisica dell'Universitá di Genova and IMEM-CNR Unitá Operativa di Genova, Via Dodecaneso 33, 15146 Genova, Italy
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24
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Poyli MA, Silkin VM, Chernov IP, Echenique PM, Muiño RD, Aizpurua J. Multiscale Theoretical Modeling of Plasmonic Sensing of Hydrogen Uptake in Palladium Nanodisks. J Phys Chem Lett 2012; 3:2556-61. [PMID: 26295874 DOI: 10.1021/jz3007723] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We study theoretically the optical properties of palladium nanodisks during hydrogen uptake. A combination of an ab initio quantum mechanical description of the Pd-H dielectric properties and a full electrodynamical study of light scattering in the H-modified Pd nanodisks allows us to trace the shift of the localized surface plasmon as a function of the H concentration in the Pd-H disk. We follow the evolution of the plasmon peak energy for different admixtures of the Pd-H α and β phases and interpret quantitatively the experimental sensitivity of the plasmon energy shift to the structural inhomogeneity upon H absorption. Our multiscale theoretical framework provides a solid background for plasmonic sensing of structural domains, as well as for identifying H saturation conditions in metal hydride systems.
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Affiliation(s)
- M Ameen Poyli
- †Centro de Física de Materiales CFM (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- ‡Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - V M Silkin
- ‡Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- ¶Departamento de Física de Materiales, Facultad de Químicas UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain
- §IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - I P Chernov
- ∥Tomsk Polytechnical University, pr. Lenina 30, 634050 Tomsk, Russia
| | - P M Echenique
- †Centro de Física de Materiales CFM (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- ‡Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- ¶Departamento de Física de Materiales, Facultad de Químicas UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain
| | - R Díez Muiño
- †Centro de Física de Materiales CFM (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- ‡Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - J Aizpurua
- †Centro de Física de Materiales CFM (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- ‡Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
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25
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Silkin VM, Díez Muiño R, Chernov IP, Chulkov EV, Echenique PM. Tuning the plasmon energy of palladium-hydrogen systems by varying the hydrogen concentration. J Phys Condens Matter 2012; 24:104021. [PMID: 22353792 DOI: 10.1088/0953-8984/24/10/104021] [Citation(s) in RCA: 8] [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] [Indexed: 05/31/2023]
Abstract
First-principles calculations are performed to obtain the dielectric function and loss spectra of bulk PdH(x). Hydrogen concentrations between x = 0 and 1 are considered. The calculated spectra are dominated by a broad peak that redshifts in energy with x. The obtained bulk dielectric function is employed to compute the loss spectra of PdH(x) spherical nanoparticles as a function of x. The dominant plasmon peak in the spherical nanoparticle is lowered in energy with respect to the bulk case. However, the dependence of the resonance energy on the hydrogen concentration is roughly similar to that in bulk.
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Affiliation(s)
- V M Silkin
- Departamento de Física de Materiales, Facultad de Químicas UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain.
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26
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Nagao T, Han G, Hoang C, Wi JS, Pucci A, Weber D, Neubrech F, Silkin VM, Enders D, Saito O, Rana M. Plasmons in nanoscale and atomic-scale systems. Sci Technol Adv Mater 2010; 11:054506. [PMID: 27877363 PMCID: PMC5090622 DOI: 10.1088/1468-6996/11/5/054506] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 01/10/2011] [Accepted: 11/05/2010] [Indexed: 05/23/2023]
Abstract
Plasmons in metallic nanomaterials exhibit very strong size and shape effects, and thus have recently gained considerable attention in nanotechnology, information technology, and life science. In this review, we overview the fundamental properties of plasmons in materials with various dimensionalities and discuss the optical functional properties of localized plasmon polaritons in nanometer-scale to atomic-scale objects. First, the pioneering works on plasmons by electron energy loss spectroscopy are briefly surveyed. Then, we discuss the effects of atomistic charge dynamics on the dispersion relation of propagating plasmon modes, such as those for planar crystal surface, atomic sheets and straight atomic wires. Finally, standing-wave plasmons, or antenna resonances of plasmon polariton, of some widely used nanometer-scale structures and atomic-scale wires (the smallest possible plasmonic building blocks) are exemplified along with their applications.
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Affiliation(s)
- Tadaaki Nagao
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
| | - Gui Han
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
| | - ChungVu Hoang
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
- Kirchhoff Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, D 69120, Heidelberg, Germany
| | - Jung-Sub Wi
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
| | - Annemarie Pucci
- Kirchhoff Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, D 69120, Heidelberg, Germany
| | - Daniel Weber
- Kirchhoff Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, D 69120, Heidelberg, Germany
| | - Frank Neubrech
- Kirchhoff Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, D 69120, Heidelberg, Germany
| | - Vyacheslav M Silkin
- Depto de Física de Materiales, Facultad de Ciencias Quimicas, Universidad del Pais Vasco, Apdo. 1072, 20080 San Sebastian/Donostia, Spain
- Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal 4, 20018 San Sebastian/Donostia, Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Dominik Enders
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
| | - Osamu Saito
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
| | - Masud Rana
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
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27
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Silkin VM, Kazansky AK, Chulkov EV, Echenique PM. Time-dependent screening of a point charge at a metal surface. J Phys Condens Matter 2010; 22:304013. [PMID: 21399345 DOI: 10.1088/0953-8984/22/30/304013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The space-time evolution of the dynamical screening charge density caused by a suddenly created point charge at the Cu(111) surface is investigated in the linear response approximation. Considering a thin slab as a model for the Cu(111) surface, we investigate the confinement effects on dynamical screening as well. The results have been obtained on the basis of self-consistent evaluation of the energy-momentum-dependent response function, taking into account the realistic surface band structure of Cu(111). At the initial stage, we observe fast long-range charge density oscillations due to excitation of the surface plasmon modes. Then we observe the propagation of the shock wave of the electron-hole excitations along the slab with velocity determined by the Fermi velocity of bulk Cu. At longer times, we have identified the propagation along the two slab surfaces of a much slower (with velocity ∼ 0.3 au, close to the Fermi velocity of the Cu(111) surface state) charge disturbance due to acoustic surface plasmon. The role of the energy band gap in the direction perpendicular to the surface in establishing the screening is also addressed.
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Affiliation(s)
- V M Silkin
- Departamento de Física de Materiales, Facultad de Química, Universidad del País Vasco, San Sebastián, Basque Country, Spain.
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28
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Borca B, Barja S, Garnica M, Sánchez-Portal D, Silkin VM, Chulkov EV, Hermanns CF, Hinarejos JJ, Vázquez de Parga AL, Arnau A, Echenique PM, Miranda R. Potential energy landscape for hot electrons in periodically nanostructured graphene. Phys Rev Lett 2010; 105:036804. [PMID: 20867790 DOI: 10.1103/physrevlett.105.036804] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Indexed: 05/29/2023]
Abstract
We explore the spatial variations of the unoccupied electronic states of graphene epitaxially grown on Ru(0001) and observed three unexpected features: the first graphene image state is split in energy; unlike all other image states, the split state does not follow the local work function modulation, and a new interfacial state at +3 eV appears on some areas of the surface. First-principles calculations explain the observations and permit us to conclude that the system behaves as a self-organized periodic array of quantum dots.
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Affiliation(s)
- B Borca
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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29
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Borisov AG, Sametoglu V, Winkelmann A, Kubo A, Pontius N, Zhao J, Silkin VM, Gauyacq JP, Chulkov EV, Echenique PM, Petek H. Pi resonance of chemisorbed alkali atoms on noble metals. Phys Rev Lett 2008; 101:266801. [PMID: 19113781 DOI: 10.1103/physrevlett.101.266801] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Indexed: 05/27/2023]
Abstract
We have performed a joint experimental and theoretical study of the unoccupied electronic structure of alkali adsorbates on the (111) surfaces of Cu and Ag. Combining angle- and time-resolved two-photon photoemission spectroscopy with wave packet propagation calculations we show that, along with the well known sigma resonance oriented along the surface normal, there exist long-lived alkali-localized resonances oriented parallel to the surface (pi symmetry). These new resonances are stabilized by the projected band gap of the substrate and emerge primarily from the mixing of the p and d Rydberg orbitals of the free alkali atom modified by the interaction with the surface.
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Affiliation(s)
- A G Borisov
- Laboratoire des Collisions Atomiques et Moléculaires, UMR CNRS-Universite Paris-Sud 8625, Bâtiment 351, Université Paris-Sud, 91405 Orsay cedex, France.
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30
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Diaconescu B, Pohl K, Vattuone L, Savio L, Hofmann P, Silkin VM, Pitarke JM, Chulkov EV, Echenique PM, Farías D, Rocca M. Low-energy acoustic plasmons at metal surfaces. Nature 2007; 448:57-9. [PMID: 17611537 DOI: 10.1038/nature05975] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Accepted: 05/29/2007] [Indexed: 11/09/2022]
Abstract
Nearly two-dimensional (2D) metallic systems formed in charge inversion layers and artificial layered materials permit the existence of low-energy collective excitations, called 2D plasmons, which are not found in a three-dimensional (3D) metal. These excitations have caused considerable interest because their low energy allows them to participate in many dynamical processes involving electrons and phonons, and because they might mediate the formation of Cooper pairs in high-transition-temperature superconductors. Metals often support electronic states that are confined to the surface, forming a nearly 2D electron-density layer. However, it was argued that these systems could not support low-energy collective excitations because they would be screened out by the underlying bulk electrons. Rather, metallic surfaces should support only conventional surface plasmons-higher-energy modes that depend only on the electron density. Surface plasmons have important applications in microscopy and sub-wavelength optics, but have no relevance to the low-energy dynamics. Here we show that, in contrast to expectations, a low-energy collective excitation mode can be found on bare metal surfaces. The mode has an acoustic (linear) dispersion, different to the dependence of a 2D plasmon, and was observed on Be(0001) using angle-resolved electron energy loss spectroscopy. First-principles calculations show that it is caused by the coexistence of a partially occupied quasi-2D surface-state band with the underlying 3D bulk electron continuum and also that the non-local character of the dielectric function prevents it from being screened out by the 3D states. The acoustic plasmon reported here has a very general character and should be present on many metal surfaces. Furthermore, its acoustic dispersion allows the confinement of light on small surface areas and in a broad frequency range, which is relevant for nano-optics and photonics applications.
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Affiliation(s)
- Bogdan Diaconescu
- Department of Physics and Material Science Program, University of New Hampshire, Durham, New Hampshire 03824, USA
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31
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Chulkov EV, Borisov AG, Gauyacq JP, Sanchez-Portal D, Silkin VM, Zhukov VP, Echenique PM. Electronic Excitations in Metals and at Metal Surfaces. Chem Rev 2006; 106:4160-206. [PMID: 17031983 DOI: 10.1021/cr050166o] [Citation(s) in RCA: 208] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E V Chulkov
- Departamento de Física de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, Apdo. 1072, 20080 San Sebastian/Donostia, Basque Country, Spain.
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32
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Lazić P, Silkin VM, Chulkov EV, Echenique PM, Gumhalter B. Extreme ultrafast dynamics of quasiparticles excited in surface electronic bands. Phys Rev Lett 2006; 97:086801. [PMID: 17026323 DOI: 10.1103/physrevlett.97.086801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Indexed: 05/12/2023]
Abstract
We develop a many-body description of the nonadiabatic dynamics of quasiparticles in surface bands valid on an extremely ultrashort time scale by combining the formalism for the calculation of quasiparticle survival probabilities with the self-consistent treatment of the electronic response of the system. Applying this approach to the benchmark Cu(111) surface, we assess the behavior and intervals of preasymptotic electron and hole dynamics in surface bands and locate the transition to the asymptotic regime of the exponential quasiparticle decay characterized by the corrected Fermi golden rule-type of transition rate. The general validity of these findings enables distinguishing the various regimes of ultrafast electron dynamics that may be revealed in time resolved experiments.
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Affiliation(s)
- P Lazić
- Donostia International Physics Center, E-20018 San Sebastian, Spain
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33
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Corriol C, Silkin VM, Sánchez-Portal D, Arnau A, Chulkov EV, Echenique PM, von Hofe T, Kliewer J, Kröger J, Berndt R. Role of elastic scattering in electron dynamics at ordered alkali overlayers on Cu(111). Phys Rev Lett 2005; 95:176802. [PMID: 16383854 DOI: 10.1103/physrevlett.95.176802] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Indexed: 05/05/2023]
Abstract
Scanning tunneling spectroscopy of p(2 x 2) Cs and Na ordered overlayers on Cu(111) reveals similar line widths of quasi-two-dimensional quantum well states despite largely different binding energies. Detailed calculations show that 50% of the line widths are due to electron-phonon scattering while inelastic electron-electron scattering is negligible. The mechanism of enhanced elastic scattering due to Brillouin zone backfolding contributes the remaining width.
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Affiliation(s)
- C Corriol
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, San Sebastian 20018, Spain
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Silkin VM, Chulkov EV, Echenique PM. Band structure versus dynamical exchange-correlation effects in surface plasmon energy and damping: a first-principles calculation. Phys Rev Lett 2004; 93:176801. [PMID: 15525102 DOI: 10.1103/physrevlett.93.176801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Indexed: 05/24/2023]
Abstract
A first-principles parameter-free calculation that includes full three-dimensional band structure and dynamical exchange correlations is reported for the dynamical surface response and surface plasmon (SP) on a simple metal prototype surface Mg(0001). We demonstrate that band structure effects have a more profound impact on the SP characteristics than dynamical exchange correlations. A comparison with jellium and one-dimensional potential evaluations shows that the band structure is of paramount importance for the correct description of the SP linewidth and also leads to a better description of the SP energy dispersion. The inclusion of the exchange-correlation kernel results in a better agreement with experimental data. We show that lateral crystal local field effects have a negligible impact on the SP properties. Significant anisotropy is predicted for the SP linewidth.
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Affiliation(s)
- V M Silkin
- Donostia International Physics Center (DIPC), P. de Manuel Lardizabal 4, 20018 San Sebastián, Basque Country, Spain
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36
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Eiguren A, Hellsing B, Reinert F, Nicolay G, Chulkov EV, Silkin VM, Hüfner S, Echenique PM. Role of bulk and surface phonons in the decay of metal surface States. Phys Rev Lett 2002; 88:066805. [PMID: 11863840 DOI: 10.1103/physrevlett.88.066805] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2001] [Indexed: 05/23/2023]
Abstract
We present a comprehensive theoretical investigation of the electron-phonon contribution to the lifetime broadening of the surface states on Cu(111) and Ag(111), in comparison with high-resolution photoemission results. The calculations, including electron and phonon states of the bulk and the surface, resolve the relative importance of the Rayleigh mode, being dominant for the lifetime at small hole binding energies. Including the electron-electron interaction, the theoretical results are in excellent agreement with the measured binding energy and temperature dependent lifetime broadening.
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Affiliation(s)
- A Eiguren
- Departmento de Física de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Químicas, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Apdo. 1072, 20018 San Sebastián/Donostia, Basque Country, Spain
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37
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Berthold W, Höfer U, Feulner P, Chulkov EV, Silkin VM, Echenique PM. Momentum-resolved lifetimes of image-potential States on cu(100). Phys Rev Lett 2002; 88:056805. [PMID: 11863766 DOI: 10.1103/physrevlett.88.056805] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2001] [Indexed: 05/23/2023]
Abstract
The dependence of the inelastic lifetime of electrons in the image-potential states of Cu(100) on their momentum parallel to the surface has been studied experimentally by means of time- and angle-resolved two-photon photoemission and theoretically by evaluating the electron self-energy within the GW approximation. The pronounced decrease of the n = 1 lifetime from 40 fs at normal emission (k(parallel) = 0) to 20 fs for k(parallel) = 0.33 A(-1) cannot be accounted for by interband decay processes to bulk states. We show that intraband transitions within the image-state band give a contribution to this decrease comparable in magnitude with the interband channel.
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Affiliation(s)
- W Berthold
- Fachbereich Physik und Zentrum für Materialwissenschaften, Philipps-Universität, D-35032 Marburg, Germany
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38
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Borisov AG, Gauyacq JP, Kazansky AK, Chulkov EV, Silkin VM, Echenique PM. Long-lived excited states at surfaces: Cs/Cu(111) and Cs/Cu(100) systems. Phys Rev Lett 2001; 86:488-491. [PMID: 11177862 DOI: 10.1103/physrevlett.86.488] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2000] [Indexed: 05/23/2023]
Abstract
One-electron and multielectron contributions to the decay of transient states in the Cs/Cu(111) and (100) systems are studied by a joined wave-packet propagation and many-body metal response approach. The long lifetime of these states is due to the Cu L and X band gaps which reduce the electron tunneling between Cs and Cu. In the (111) case, the decay is mainly by inelastic e-e interaction, whereas in the (100) case, electron tunneling is dominating. This accounts very well for the experimental findings [Bauer et al., Phys. Rev. B 55, 10 040 (1997) and Ogawa et al., Phys. Rev. Lett. 82, 1931 (1999)].
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Affiliation(s)
- A G Borisov
- Laboratoire des Collisions Atomiques et Moléculaires, Unité Mixte de Recherche CNRS-Université Paris Sud UMR 8625, Bâtiment 351, Université Paris-Sud, 91405 Orsay Cedex, France
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Abstract
A long-standing discrepancy between experimental and theoretical values for the lifetimes of holes in the surface-state electron bands on noble metal surfaces is resolved; previous determinations of both are found to have been in error. The ability of the scanning tunneling microscope to verify surface quality before taking spectroscopic measurements is used to remove the effects of defect scattering on experimental lifetimes, found to have been a significant contribution to prior determinations. A theoretical treatment of inelastic electron-electron scattering is developed that explicitly includes intraband transitions within the surface state band. In our model, two-dimensional decay channels dominate the electron-electron interactions that contribute to the hole decay and are screened by the electron states of the underlying three-dimensional electron system.
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Affiliation(s)
- J Kliewer
- RWTH Aachen, II. Physikalisches Institut, D-52056 Aachen, Germany. Institut fur Experimentelle und Angewandte Physik, Christian-Albrechts-Universitat zu Kiel, D-24098 Kiel, Germany. Departamento de Fisica de Materiales, Faculta
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