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Lian C, Hu SQ, Zhang J, Cheng C, Yuan Z, Gao S, Meng S. Integrated Plasmonics: Broadband Dirac Plasmons in Borophene. PHYSICAL REVIEW LETTERS 2020; 125:116802. [PMID: 32976016 DOI: 10.1103/physrevlett.125.116802] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/30/2019] [Accepted: 08/12/2020] [Indexed: 06/11/2023]
Abstract
The past decade has witnessed numerous discoveries of two-dimensional (2D) semimetals and insulators, whereas 2D metals were rarely identified. Borophene, a monolayer boron sheet, has recently emerged as a perfect 2D metal with unique electronic properties. Here we study collective excitations in borophene, which exhibit two major plasmon modes with low damping rates extending from the infrared to ultraviolet regime. The anisotropic 1D plasmon originates from electronic transitions of tilted Dirac cones in borophene, analogous to that in extreme doped graphene. These features enable borophene as an integrated platform of 1D, 2D, and Dirac plasmons, promising for directional polariton transport and broadband optical communication in next-generation optoelectronic devices.
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Affiliation(s)
- Chao Lian
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shi-Qi Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jin Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cai Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhe Yuan
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Shiwu Gao
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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Wang S, Zhao S, Shi Z, Wu F, Zhao Z, Jiang L, Watanabe K, Taniguchi T, Zettl A, Zhou C, Wang F. Nonlinear Luttinger liquid plasmons in semiconducting single-walled carbon nanotubes. NATURE MATERIALS 2020; 19:986-991. [PMID: 32231241 DOI: 10.1038/s41563-020-0652-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
Interacting electrons confined in one dimension are generally described by the Luttinger liquid formalism, where the low-energy electronic dispersion is assumed to be linear and the resulting plasmonic excitations are non-interacting. Instead, a Luttinger liquid in one-dimensional materials with nonlinear electronic bands is expected to show strong plasmon-plasmon interactions, but an experimental demonstration of this behaviour has been lacking. Here, we combine infrared nano-imaging and electronic transport to investigate the behaviour of plasmonic excitations in semiconducting single-walled carbon nanotubes with carrier density controlled by electrostatic gating. We show that both the propagation velocity and the dynamic damping of plasmons can be tuned continuously, which is well captured by the nonlinear Luttinger liquid theory. These results contrast with the gate-independent plasmons observed in metallic nanotubes, as expected for a linear Luttinger liquid. Our findings provide an experimental demonstration of one-dimensional electron dynamics beyond the conventional linear Luttinger liquid paradigm and are important for understanding excited-state properties in one dimension.
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Affiliation(s)
- Sheng Wang
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sihan Zhao
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - Zhiwen Shi
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, China
| | - Fanqi Wu
- Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA
| | - Zhiyuan Zhao
- Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA
| | - Lili Jiang
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | | | - Alex Zettl
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Kavli Energy NanoScience Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Chongwu Zhou
- Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Feng Wang
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Kavli Energy NanoScience Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Kaur K, Sharma A, Garg V, Moudgil RK. Dynamic correlation effects on correlational properties of finite-temperature quasi-one-dimensional electron gas. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:335403. [PMID: 32289766 DOI: 10.1088/1361-648x/ab88f3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
We have studied correlational properties of quasi-one-dimensional electron gas at finite temperatureTby incorporating the dynamics of electron correlations within the quantum version of the self-consistent mean-field approach of Singwi, Tosi, Land, and Sjölander. Static structure factor, pair-correlation function, static density susceptibility, excess kinetic energy, and free correlation energy are calculated covering a wide range of temperature and electron number density. As at absolute zero temperature, the inclusion of dynamics of correlations results in stronger spatial electron correlations, with a pronounced peak in the static structure factor at wave vectorq∼ 3.5kF, which grows further with decreasing electron density. Below a critical density, the static density susceptibility seems to diverge at this value ofq, signaling a transition from liquid to the Wigner crystal state-a prediction in qualitative agreement with recent simulations and experiment. However, thermal effects tend to impede crystallization with the consequence that the critical density decreases significantly with risingT. On the other hand, the pair-correlation function at short range exhibits a non-monotonic dependence onT, initially becoming somewhat stronger with risingTand then weakening continuously above a sufficiently highT. The calculated free correlation energy shows a noticeable dependence onT, with its magnitude increasing with increase inT. Further, we have looked into the effect of temperature on the frequency-dependence of dynamic local-field correction factor and the plasmon dispersion. It is found that with risingTthe dynamics of correlations weakens, and the plasmon frequency exhibits a blue shift. Wherever interesting, we have compared our results with the lower-order approximate calculations and zero-Tquantum Monte Carlo simulations.
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Affiliation(s)
- Kulveer Kaur
- Department of Physics, Punjabi University, Patiala - 147 002, India
| | - Akariti Sharma
- Department of Physics, Punjabi University, Patiala - 147 002, India
| | - Vinayak Garg
- Department of Physics, Punjabi University, Patiala - 147 002, India
| | - R K Moudgil
- Department of Physics, Kurukshetra University, Kurukshetra - 136 119, India
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Wang S, Wu F, Watanabe K, Taniguchi T, Zhou C, Wang F. Metallic Carbon Nanotube Nanocavities as Ultracompact and Low-loss Fabry-Perot Plasmonic Resonators. NANO LETTERS 2020; 20:2695-2702. [PMID: 32134275 DOI: 10.1021/acs.nanolett.0c00315] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Plasmonic resonators enable deep subwavelength manipulation of light matter interactions and have been intensively studied both in fundamental physics as well as for potential technological applications. While various metallic nanostructures have been proposed as plasmonic resonators, their performances are rather limited at mid- and far-infrared wavelengths. Recently, highly confined and low-loss Luttinger liquid plasmons in metallic single-walled carbon nanotubes (SWNTs) have been observed at infrared wavelengths. Here, we tailor metallic SWNTs into ultraclean nanocavities by advanced scanning probe lithography and investigate plasmon modes in these individual nanocavities by infrared nanoimaging. The dependence of mode evolutions on cavity length and excitation wavelength can be captured by a Fabry-Perot resonator model of a plasmon nanowaveguide terminated by highly reflective ends. Plasmonic resonators based on SWNT nanocavities approach the ultimate plasmon confinement limit and open the door to the strong light-matter coupling regime, which may enable various nanophotonic applications.
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Affiliation(s)
- Sheng Wang
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Fanqi Wu
- Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Chongwu Zhou
- Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
- Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Feng Wang
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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Lichtenstein T, Mamiyev Z, Jeckelmann E, Tegenkamp C, Pfnür H. Anisotropic 2D metallicity: plasmons in Ge(1 0 0)-Au. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:175001. [PMID: 30695765 DOI: 10.1088/1361-648x/ab02c5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The low-energy plasmonic excitations of the Ge(0 0 1)-Au close to one monolayer coverage of Au were investigated by momentum-resolved high resolution electron energy loss spectroscopy. A very weak plasmonic loss was identified dispersing along the chain direction of the [Formula: see text] formed at these Au coverages. The measured dispersion was compared with the Tomonaga-Luttinger-liquid (TLL) model and with a model for an anisotropic Fermi liquid. Using the TLL model both for single and arrays of wires, no consistent picture turned up that could describe all available data. On the contrary, a quasi-one-dimensional model of a confined 2D electron gas gave a satisfactorily consistent description of the data. From these results for the collective low-energy excitations we conclude that the Ge(0 0 1)-Au system is reasonably well described by a strongly anisotropic 2D Fermi liquid, but is incompatible with a TLL.
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Affiliation(s)
- T Lichtenstein
- Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany
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Lichtenstein T, Tegenkamp C, Pfnür H. Lateral electronic screening in quasi-one-dimensional plasmons. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:354001. [PMID: 27384978 DOI: 10.1088/0953-8984/28/35/354001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The properties of one-dimensional (1D) plasmons are rather unexplored. We investigated the plasmonic collective excitations, measured as one-dimensional plasmon dispersions with electron energy loss spectroscopy, highly resolved both in energy and lateral momentum, for both phases of Au induced chains on stepped Si(553) substrates. We observe 1D dispersions that are strongly influenced by the lateral chain width and by the interchain coupling. Indications for the existence of two different plasmons originating from two surface bands of the systems are given for the low coverage phase.
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Affiliation(s)
- T Lichtenstein
- Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany
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Steffen W, Kull HJ. Relaxation of plasma waves in Fermi-degenerate quantum plasmas. Phys Rev E 2016; 93:033207. [PMID: 27078475 DOI: 10.1103/physreve.93.033207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 11/07/2022]
Abstract
Plasma waves in a Fermi-degenerate quantum plasma are studied in the framework of the Vlasov-Poisson self-consistent-field theory. A complete time-dependent analytical solution of the initial-value problem is obtained for a multistream model both by stationary-wave and Laplace-transform methods. In the continuum limit, the excitation spectrum can be expressed by the imaginary part of the response function to the initial perturbations. The relaxation of plasma waves is discussed for one-dimensional systems with both Fermi and Maxwellian statistics. Apart from the usual exponential Landau damping, regimes of sub- and superexponential damping can be identified due to the phase relaxation of single-particle excitations. In addition, beat waves and echoes are discussed.
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Affiliation(s)
- W Steffen
- Institute for Theory of Statistical Physics, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
| | - H-J Kull
- Institute for Theory of Statistical Physics, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
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Liang Y, Yang L. Carrier plasmon induced nonlinear band gap renormalization in two-dimensional semiconductors. PHYSICAL REVIEW LETTERS 2015; 114:063001. [PMID: 25723215 DOI: 10.1103/physrevlett.114.063001] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Indexed: 06/04/2023]
Abstract
In reduced-dimensional semiconductors, doping-induced carrier plasmons can strongly couple with quasiparticle excitations, leading to a significant band gap renormalization. However, the physical origin of this generic effect remains obscure. We develop a new plasmon-pole theory that efficiently and accurately captures this coupling. Using monolayer MoS(2) and MoSe(2) as prototype two-dimensional (2D) semiconductors, we reveal a striking band gap renormalization above 400 meV and an unusual nonlinear evolution of their band gaps with doping. This prediction significantly differs from the linear behavior that is observed in one-dimensional structures. Notably, our predicted band gap renormalization for MoSe(2) is in excellent agreement with recent experimental results. Our developed approach allows for a quantitative understanding of many-body interactions in general doped 2D semiconductors and paves the way for novel band gap engineering techniques.
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Affiliation(s)
- Yufeng Liang
- Department of Physics and Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Li Yang
- Department of Physics and Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
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Moudgil RK, Garg V, Pathak KN. Confinement and correlation effects on plasmons in an atom-scale metallic wire. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:135003. [PMID: 21389506 DOI: 10.1088/0953-8984/22/13/135003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have studied the effect of confinement and correlations on the plasmon dispersion in an atom-scale metallic wire by determining the electron density response function. The wire electrons are modelled as comprising a quasi-one-dimensional homogeneous gas, with different transverse confinement models. The response function is calculated by including electron correlations beyond the random-phase approximation within the self-consistent mean-field approach of Singwi et al (1968 Phys. Rev. 176 589). The plasmon dispersion results are found to be in very good agreement with the recent electron-energy-loss spectroscopy measurements by Nagao et al (2006 Phys. Rev. Lett. 97 116802). However, our predictions are found to depend strongly on the nature of the confinement model, the structure of the one-dimensional electronic band and the electron effective mass, implying a crucial role for the wire structure.
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Affiliation(s)
- R K Moudgil
- Department of Physics, Kurukshetra University, Kurukshetra, India.
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Hernández ES. Spin-zero sound in one- and quasi-one-dimensional 3He. PHYSICAL REVIEW LETTERS 2002; 89:185301. [PMID: 12398612 DOI: 10.1103/physrevlett.89.185301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2001] [Indexed: 05/24/2023]
Abstract
The zero sound spectrum of fluid 3He confined to a cylindrical shell is examined for configurations characterizing strictly one-dimensional and quasi-one-dimensional regimes. It is shown that the restricted dimensionality makes room to the possibility of spin-zero sound for the attractive particle-hole interaction of liquid helium. This fact can be related to the suppression of phase instabilities and thermodynamic phase transitions in one dimension.
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Affiliation(s)
- E S Hernández
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
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Hughes S, Citrin DS. High-field franz-keldysh effect and exciton ionization in semiconductor quantum wires. PHYSICAL REVIEW LETTERS 2000; 84:4228-4231. [PMID: 10990652 DOI: 10.1103/physrevlett.84.4228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/1999] [Indexed: 05/23/2023]
Abstract
We investigate the Franz-Keldysh effect and exciton ionization in semiconductor quantum wires. Absorption spectra are calculated near the band gap by solution of the low-density semiconductor Bloch equations in real space. The Sommerfeld factor and field-induced tunnel ionization of the exciton significantly affect the continuum portion of the absorption spectrum and remove the well known divergence problem associated with the 1D density of states at all field strengths. For reasonable electric field strengths substantial and tunable absorption oscillations appear above the band gap. Moreover, for very large fields, transparency can be achieved in the continuum for certain spectral positions.
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Affiliation(s)
- S Hughes
- Department of Physics, University of Surrey, Guildford, Surrey GU2 5XH, United Kingdom
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