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Related papers: Tuning topological disorder in MgB$_{2}$

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InAs/GaSb hosts a broken gap band alignment that has been shown to generate helical topological edge states. Upon the introduction of Mn into the structure, it has been predicted to host a quantized anomalous Hall effect. Here, we show that…

We compute the anharmonic shift of the phonon frequencies in MgB2, using density functional theory. We explicitly take into account the scattering between different phonon modes at different q-points in the Brillouin zone. The shift of the…

Superconductivity · Physics 2009-11-10 Michele Lazzeri , Matteo Calandra , Francesco Mauri

We demonstrate that disorder in photonic crystals could lead to pronounced modification of spontaneous emission rate in the frequency region corresponding to the photonic band gap (PBG). Depending on the amount of disorder, two different…

We present a combined experimental and computational study of two-dimensional molybdenum disulfde (MoS2) and the effect of temperature on the frequency shifts of the Raman-active E2g and A1g modes in the monolayer. While both peaks show an…

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…

Structural disorder can improve the optical properties of metasurfaces, whether it is emerging from some large-scale fabrication methods, or explicitly designed and built lithographically. Correlated disorder, induced by a minimum…

We analyse a model where the anomalies of the bond-stretching LO phonon mode are caused by the coupling to electron dynamic response in the form of a damped oscillator and explore the possibility to reconstruct the spectrum of the latter…

Superconductivity · Physics 2012-05-16 S. Cojocaru , R. Citro , M. Marinaro

This work revisits the physics giving rise to the carbon nanotubes phonon bands in the mid- infrared. Our measurements of doped and undoped samples of single-walled carbon nanotubes in Fourier transform infrared spectroscopy show that the…

Using infrared (IR) and Raman spectroscopies combined with high-resolution x-ray diffraction, we address several controversial aspects of altermagnetic $\alpha$-MnTe. We show that mechanical stress applied to crystals of this material…

We analyse Raman-induced self-frequency shift in two-component solitons supported by both quadratic and cubic nonlinearities. Treating Raman terms as a perturbation, we derive expressions for soliton velocity and frequency shifts of the…

Optics · Physics 2020-08-26 William R. Rowe , Dmitry V. Skryabin , Andrey V. Gorbach

The Raman selection rules arise from the crystal symmetry and then determine the Raman activity and polarization of scattered phonon modes. However, these selection rules can be broken in resonant process due to the strong electron-phonon…

Materials Science · Physics 2021-02-09 Qing-Hai Tan , Kai-Xuan Xu , Yu-Jia Sun , Xue-Lu Liu , Yuan-Fei Gao , Shu-Liang Ren , Ping-Heng Tan , Jun Zhang

MnBi$_{2}$Te$_{4}$, the first topological insulator with inherent magnetic ordering, has attracted significant attention recently for providing a platform to realize several exotic quantum phenomena at relatively higher temperatures. In…

We have studied the influence of disorder induced by electron irradiation on the normal state resistivities $\rho(T)$ of optimally and underdoped YBa2CuOx single crystals, using pulsed magnetic fields up to 60T to completely restore the…

Superconductivity · Physics 2008-02-13 F. Rullier-Albenque , H. Alloul , F. Balakirev , C. Proust

The Raman spectra of two G-bands and a radial breathing mode (RBM) of unfilled and filled single-wall semiconducting and metallic carbon nanotubes have been investigated theoretically, in the presence of electron-phonon and phonon-phonon…

Other Condensed Matter · Physics 2009-11-13 S. Gayen , S. N. Behera , S. M. Bose

The vibrational properties of 2H-TaSe$_{2-x}$S$_x$ ($0 \le x \le 2$) single crystals were probed using Raman spectroscopy and density functional theory calculations. The end members revealed two out of four symmetry-predicted Raman active…

Disorder inevitably exists in realistic samples, manifesting itself in various exotic properties for the topological states. In this paper, we summarize and briefly review work completed over the last few years, including our own, regarding…

Mesoscale and Nanoscale Physics · Physics 2017-12-06 Binglan Wu , Juntao Song , Jiaojiao Zhou , Hua Jiang

We use first-principles density-functional calculations to determine the frequency shift of the A$'_1$-${\bf K}$ phonon (Raman D band) in monolayer graphene, as a function of the charge doping. A detailed DFT study on the electron-phonon…

Materials Science · Physics 2007-05-23 Srijan Kumar Saha , U. V. Waghmare , H. R. Krishnamurthy , A. K. Sood

We report the electronic properties of two-dimensional systems made of graphene nanoribbons which are patterned with ad-atoms in two separated regions. Due to the extra electronic confinement induced by the presence of the impurities, we…

Mesoscale and Nanoscale Physics · Physics 2015-09-25 J. W. González , L. Rosales , M. Pacheco , A. Ayuela

We theoretically investigate the frequency dependence of phonon-induced current noise in armchair carbon nanotubes at room temperature. Our results reveal the emergence of multiple resonance peaks in the high-frequency regime, which cannot…

Mesoscale and Nanoscale Physics · Physics 2026-01-19 Raimu Akimoto , Aina Sumiyoshi , Takahiro Yamamoto

Polarized Raman scattering spectra of the K_xCo_{2-y}Se_2 single crystals reveal the presence of two phonon modes, assigned as of the A_{1g} and B_{1g} symmetry. Absence of additional modes excludes the possibility of vacancy ordering,…

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