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Related papers: Coherent Dirac plasmons in topological insulators

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Our direct atomic simulations reveal that a thermally activated phonon mode involves a large population of elastic wavepackets. These excitations are characterized by a wide distribution of lifetimes and coherence times expressing particle-…

Mesoscale and Nanoscale Physics · Physics 2021-05-26 Zhongwei Zhang , Yangyu Guo , Marc Bescond , Jie Chen , Masahiro Nomura , Sebastian Volz

We observe pronounced oscillations in the differential reflectivity of a ferromagnetic InMnAs/GaSb heterostructure using two-color pump-probe spectroscopy. Although originally thought to be associated with the ferromagnetism, our studies…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 J. Wang , Y. Hashimoto , J. Kono , A. Oiwa , H. Munekata , G. D. Sanders , C. J. Stanton

Starting from the Dirac equation, the relativistic quantum hydrodynamic equations for Dirac electrons on a surface of a three dimensional-topological insulator (TI) are derived and numerically solved to study the spin plasmons. The surface…

Mesoscale and Nanoscale Physics · Physics 2014-05-27 Ya Zhang , Jianwei Cui , Wei Jiang , Lin Yi

We theoretically investigate the plasmonic coupling in heterogenous Al-Ag nanorod dimer. A pronounced Fano dip is found in the extinction spectrum produced by the destructive interference between the bright dipole mode from a short Al…

Optics · Physics 2015-06-18 Xueting Ci , Botao Wu , Min Song , Yan Liu , Gengxu Chen , E Wu , Heping Zeng

Ferromagnetic resonance is used to reveal features of the buried electronic band structure at interfaces between ferromagnetic metals and topological insulators. By monitoring the evolution of magnetic damping, the application of this…

Dirac fermions exist in many solid state systems including graphene, silicene and other two dimensional membranes such as are found in group VI dichalcogenides, as well as on the surface of some insulators where such states are protected by…

Mesoscale and Nanoscale Physics · Physics 2013-07-10 Zhou Li , J. P. Carbotte

The phase picked up by a graphene plasmon upon scattering by an abrupt edge is commonly assumed to be $-\pi$. Here, it is demonstrated that for high plasmon momenta this reflection phase is $\approx -3\pi/4$, virtually independent on either…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 A. Yu. Nikitin , T. Low , L. Martin-Moreno

A Fano-like phonon resonance is observed in few-layer (~3) graphene at room temperature using infrared Fourier transform spectroscopy. This Fano resonance is the manifestation of a strong electron-phonon interaction between the discrete…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Zhihong Liu , Xiaoxiang Lu , Peng Peng , Wei Wu , Steven Pei , Qingkai Yu , Jiming Bao

We show that electron-phonon interactions can alter the topological properties of Dirac insulators and semimetals, both at zero and nonzero temperature. Contrary to the common belief that increasing temperature always destabilizes…

Strongly Correlated Electrons · Physics 2013-01-28 Ion Garate

We explore the collective density oscillations of a collection of charged massive Dirac particles, in one, two and three dimensions and their one dimensional superlattice. We calculate the long wavelength limit of the dynamical polarization…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Rashi Sachdeva , Anmol Thakur , Giovanni Vignale , Amit Agarwal

We demonstrate theoretically the coexistence of Dirac semimetal and topological insulator phases in InSb/$\alpha$-Sn conventional semiconductor superlattices, based on advanced first-principles calculations combined with low-energy $k\cdot…

Materials Science · Physics 2016-07-18 Jian-Peng Sun , Jia-ji Zhu , Dong Zhang , Kai Chang

We calculate the dynamic polarizability under the random phase approximation for the dice lattice. This two-dimensional system gives rise to massless Dirac fermions with pseudospin-1 in the low-energy quantum excitation spectrum, providing…

Mesoscale and Nanoscale Physics · Physics 2016-05-04 John D. Malcolm , Elisabeth J. Nicol

The theoretical assertion that the Fano asymmetry parameter and the asymptotic initial phase of a harmonic oscillator interacting with a continuum are interrelated is experimentally verified. By an example of coherent fully symmetric A1g…

Mesoscale and Nanoscale Physics · Physics 2015-04-23 O. V. Misochko , M. V. Lebedev

Topological insulators (TIs) are a new quantum state of matter. Their surfaces and interfaces act as a topological boundary to generate massless Dirac fermions with spin-helical textures. Investigation of fermion dynamics near the Dirac…

Rapidly developing photonics brings many interesting resonant optical phenomena, in which the Fano resonance (FR) always intrigues researchers because of its applications in optical switching and sensing. However, its sensitive dependence…

Optics · Physics 2021-07-13 Chang-Yin Ji , Yongyou Zhang , Bingsuo Zou , Yugui Yao

When a two-level quantum dot and a plasmonic metal nanoantenna are resonantly coupled by the electromagnetic near field, the system can exhibit a Fano resonance, resulting in a transparency dip in the optical spectrum of the coupled system.…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Raman A. Shah , Norbert F. Scherer , Matthew Pelton , Stephen K. Gray

We propose two novel two-dimensional topological Dirac materials, planar PtN4C2 and Pt2N8C6, which exhibit graphene-like electronic structures with linearly dispersive Dirac-cone states exactly at the Fermi level. Moreover, the Dirac cone…

Materials Science · Physics 2022-07-20 Jingping Dong , Chuhan Wang , Xinlei Zhao , Miao Gao , Xun-Wang Yan , Fengjie Ma , Zhong-Yi Lu

Zone-folded acoustic phonons (6 THz) in 4H silicon carbide (SiC) have been coherently excited using a femtosecond near-infrared pulse and measured through transient reflectivity with a pump and probe protocol. Their amplitude is coherently…

In both particle and wave descriptions of phonons, the dense, aperiodically arranged interfaces in aperiodic superlattices are expected to strongly attenuate thermal transport due to phonon-interface scattering or broken long-range…

Materials Science · Physics 2024-09-04 Theodore Maranets , Yan Wang

Mechanism of the Fano resonances in planar metamaterials demonstrate based on the coupled two-oscillator model. We have described the optical spectrums like reflectance and transmittance near the resonances of bright mode (continuum mode)…

Optics · Physics 2016-05-04 Song-Kum Song , Song-Jin Im