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相关论文: Surface Phonons in the Topological Insulators Bi2S…

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We determine the nature of coupled phonons and magnetic excitations in AlFeO3 using inelastic light scattering from 5 K to 315 K covering a spectral range from 100-2200 cm-1 and complementary first-principles density functional theory-based…

We have performed polarized Raman scattering measurements on the newly discovered superconductor Ta$_{4}$Pd$_{3}$Te$_{16}$ ($T_c = 4.6$ K). We observe twenty-eight out of thirty-three Raman active modes, with frequencies in good accordance…

超导电性 · 物理学 2015-11-25 D. Chen , P. Richard , Z. -D. Song , W. -L. Zhang , S. -F. Wu , W. H. Jiao , Z. Fang , G. -H. Cao , H. Ding

We report on a >100-fold enhancement of Raman responses from Bi2Se3 thin films if laser photon energy switches from 2.33 eV (532 nm) to 1.58 eV (785 nm), which is due to direct optical coupling to Dirac surface states (SS) at the resonance…

介观与纳米尺度物理 · 物理学 2015-06-23 Yuri D. Glinka , Sercan Babakiray , Trent A. Johnson , David Lederman

We report crystal growth and Raman spectroscopy characterization of pure and mixed bulk topological insulators. The series comprises of both binary and ternary tetradymite topological insulators. We analyzed in detail the Raman peaks of…

材料科学 · 物理学 2020-12-02 Deepak Sharma , M. M. Sharma , R. S. Meena , V. P. S. Awana

Raman measurements of a Fano-type surface phonon mode associated with Dirac surface states (SS) in Bi2Se3 topological insulator thin films allowed an unambiguous determination of the electron-phonon coupling strength in Dirac SS as a…

介观与纳米尺度物理 · 物理学 2015-10-28 Yuri D. Glinka , Sercan Babakiray , David Lederman

We used low-energy, momentum-resolved inelastic electron scattering to study surface collective modes of the three-dimensional topological insulators Bi$_2$Se$_3$ and Bi$_{0.5}$Sb$_{1.5}$Te$_{3-x}$Se$_{x}$. Our goal was to identify the…

Bi2Se3 is theoretically predicted1 2and experimentally observed2,3 to be a three dimensional topological insulator. For possible applications, it is important to understand the electronic structure of the planar device. In this work,…

Bi2Se3 is a prototypical topological insulator which has a small band gap (~0.3 eV) and topologically protected conducting surface states. This material exhibits quite strong thermoelectric effects. Here we show in a mechanically exfoliated…

A scheme is proposed to electrically measure the spin-momentum coupling in the topological insulator surface state by injection of spin polarized electrons from silicon. As a first approach, devices were fabricated consisting of thin…

介观与纳米尺度物理 · 物理学 2015-06-05 C. Ojeda-Aristizabal , M. S. Fuhrer , N. P Butch , J. Paglione , I. Appelbaum

We report the first measurements of phonon dispersion curves on the (001) surface of the strong three-dimensional topological insulator Bi2Se3. The surface phonon measurements were carried out with the aid of coherent helium beam surface…

材料科学 · 物理学 2015-03-19 Xuetao Zhu , L. Santos , R. Sankar , S. Chikara , C. Howard , F. C. Chou , C. Chamon , M. El-Batanouny

Gapless surface states on topological insulators are protected from elastic scattering on non-magnetic impurities which makes them promising candidates for low-power electronic applications. However, for wide-spread applications, these…

强关联电子 · 物理学 2013-07-04 Z. -H. Pan , E. Vescovo , A. V. Fedorov , G. D. Gu , T. Valla

Topological insulators represent novel phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport…

介观与纳米尺度物理 · 物理学 2015-05-14 Hailin Peng , Keji Lai , Desheng Kong , Stefan Meister , Yulin Chen , Xiao-Liang Qi , Shou-Cheng Zhang , Zhi-Xun Shen , Yi Cui

We characterize the topological insulator Bi$_2$Se$_3$ using time- and angle- resolved photoemission spectroscopy. By employing two-photon photoemission, a complete picture of the unoccupied electronic structure from the Fermi level up to…

We theoretically consider temperature and density-dependent electron-phonon interaction induced many-body effects in the two-dimensional (2D) metallic carriers confined on the surface of the 3D topological insulator (e.g. Bi$_2$Se$_3$). We…

介观与纳米尺度物理 · 物理学 2013-08-21 S. Das Sarma , Qiuzi Li

We investigate the band dispersion and the spin texture of topologically protected surface states in the bulk topological insulators Bi2Se3 and Bi2Te3 by first-principles methods. Strong spin-orbit entanglement in these materials reduces…

介观与纳米尺度物理 · 物理学 2015-03-17 Oleg V. Yazyev , Joel E. Moore , Steven G. Louie

Plasmons, the collective excitations of electrons in the bulk or at the surface, play an important role in the properties of materials, and have generated the field of Plasmonics. We report the observation of a highly unusual acoustic…

Resonance Raman scattering, a very effective and sensitive technique for atomically thin semiconducting transition metal dichalcogenide, can be used to observe the phonons from the entire Brillouin zone. In addition to the significance of…

材料科学 · 物理学 2023-02-06 Deepu Kumar , Nasaru Khan , Rahul Kumar , Mahesh Kumar , Pradeep Kumar

Temperature-dependent Raman spectra of TbMnO$_3$ from 5 K to 300 K in the spectral range of 200 to 1525 cm$^{-1}$ show five first-order Raman allowed modes and two high frequency modes. The intensity ratio of the high frequency Raman band…

强关联电子 · 物理学 2010-04-12 Pradeep Kumar , Surajit Saha , D. V. S. Muthu , J. R. Sahu , A. K. Sood , C. N. R. Rao

We formulate and apply a theory of electron-phonon interactions for the surface state of a strong topological insulator. Phonons are modelled using an isotropic elastic continuum theory with stress-free boundary conditions and interact with…

介观与纳米尺度物理 · 物理学 2011-07-01 Sébastien Giraud , Reinhold Egger

We report inelastic light scattering studies on Ca(Fe0.97Co0.03)2As2 in a wide spectral range of 120-5200 cm-1 from 5K to 300K, covering the tetragonal to orthorhombic structural transition as well as magnetic transition at Tsm ~ 160K. The…

超导电性 · 物理学 2014-07-11 Pradeep Kumar , D. V. S. Muthu , L. Harnagea , S. Wurmehl , B. Büchner , A. K. Sood