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Related papers: Phonon anharmonicities in graphite and graphene

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The temperature dependence of the phonon spectrum in the superconducting transition metal dichalcogenide 2H-NbS$_2$ is measured by diffuse and inelastic x-ray scattering. A deep, wide and strongly temperature dependent softening, of the two…

We develop a theory for the renormalization of the phonon energy dispersion in graphene due to the combined effects of both Coulomb and electron-phonon (e-ph) interactions. We obtain the renormalized phonon energy spectrum by an exact…

Materials Science · Physics 2009-11-13 Wang-Kong Tse , Ben Yu-Kuang Hu , S. Das Sarma

The lattice thermal conductivity of graphene is evaluated using a microscopic model that takes into account the lattice's discrete nature and the phonon dispersion relation within the Brillouin zone. The Boltzmann transport equation is…

Soft Condensed Matter · Physics 2024-01-18 J. Chen , Y. Liu

We measured the temperature dependent infrared reflectivity spectra of MnF2 between 4 K and room temperature. We show that the phonon spectrum undergoes a strong renormalization at TN. The ab-initio calculation we performed on this compound…

Materials Science · Physics 2010-10-20 R. Schleck , Y. Nahas , R. P. S. M. Lobo , J. Varignon , M. B. Lepetit , C. S. Nelson , R. L. Moreira

The electron-phonon interaction in monolayer graphene is investigated by using density functional perturbation theory. The results indicate that the electron-phonon interaction strength is of comparable magnitude for all four in-plane…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 K. M. Borysenko , J. T. Mullen , E. A. Barry , S. Paul , Y. G. Semenov , J. M. Zavada , M. Buongiorno Nardelli , K. W. Kim

Raman spectra of the MgB2 ceramic samples were measured as a function of pressure up to 32 GPa at room temperature. The spectrum at normal conditions contains a very broad peak at ~590 cm-1 related to the E2g phonon mode. The frequency of…

Materials Science · Physics 2009-11-07 K. P. Meletov , J. Arvanitidis , M. P. Kulakov , N. N. Kolesnikov , G. A. Kourouklis

Using non-equilibrium molecular dynamics method(NEMD), we have found that the thermal conductivity of multilayer graphene nanoribbons monotonously decreases with the increase of the number of layers, such behavior can be attributed to the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Hai-Yuan Cao , Zhi-Xin Guo , Hongjun Xiang , Xin-Gao Gong

A simple model for flexural phonons in graphite (and graphene, corresponding to the limiting case of infinite distance between carbon planes) is proposed, in which the local dipolar moment is assumed to be proportional to the curvature of…

Mesoscale and Nanoscale Physics · Physics 2010-07-16 Konstantin L. Metlov

Heat transport by acoustic phonons in 2D materials is fundamentally different from that in 3D crystals because the out-of-plane phonons propagate in a unique way that strongly depends on tension and bending rigidity. Since in-plane and…

Mesoscale and Nanoscale Physics · Physics 2022-04-15 H. Liu , M. Lee , M. Šiškins , H. S. J. van der Zant , P. G. Steeneken , G. J. Verbiest

We present a first-principles investigation of the phonon-induced electron self-energy in graphene. The energy dependence of the self-energy reflects the peculiar linear bandstructure of graphene and deviates substantially from the usual…

Materials Science · Physics 2007-08-23 Cheol-Hwan Park , Feliciano Giustino , Marvin L. Cohen , Steven G. Louie

Temperature dependence of vibrational modes in semiconductors depends on lattice thermal expansion and anharmonic phonon-phonon scattering. Evaluating the two contributions from experimental data is not straightforward, especially for…

We study the infrared conductivity of graphene at finite chemical potential and temperature taking into account the effect of phonons and disorder due to charged impurities and unitary scatterers. The screening of the long-range Coulomb…

Mesoscale and Nanoscale Physics · Physics 2008-10-16 N. M. R. Peres , T. Stauber , A. H. Castro Neto

Inelastic phonon scattering in graphene field-effect transistors (FETs) is studied by numerically solving the Boltzmann transport equation in three dimensional real and phase spaces (x, kx, ky). A kink behavior due to ambipolar transport…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Jyotsna Chauhan , Jing Guo

Polarized Raman scattering spectra of superconducting K$_x$Fe$_{2-y}$Se$_2$ and nonsuperconducting K$_{0.8}$Fe$_{1.8}$Co$_{0.2}$Se$_2$ single crystals were measured in a temperature range from 10 K up to 300 K. Two Raman active modes from…

Materials Science · Physics 2016-09-20 M. Opačić , N. Lazarević , M. Šćepanović , Hyejin Ryu , Hechang Lei , C. Petrovic , Z. V. Popović

We have calculated the implicit shift for various modes of frequency in a pure graphene sheet. Thermal expansion and Gr\"uneisen parameter which are required for implicit shift calculation have already been studied and reported. For this…

Mesoscale and Nanoscale Physics · Physics 2020-05-22 Sarita Mann , V. K. Jindal

We show that the electron-phonon coupling in graphene, in contrast with the non-relativistic two-dimensional electron gas, leads to shifts in the phonon frequencies that are non-trivial functions of the electronic density. These shifts can…

Strongly Correlated Electrons · Physics 2013-05-29 A. H. Castro Neto , Francisco Guinea

Phonon self-energy corrections have mostly been studied theoretically and experimentally for phonon modes with zone-center (q = 0) wave-vectors. Here, gate-modulated Raman scattering is used to study phonons of a single layer of graphene…

Mesoscale and Nanoscale Physics · Physics 2012-08-02 P. T. Araujo , D. L. Mafra , K. Sato , R. Saito , J. Kong , M. S. Dresselhaus

We investigate the phonon thermal conductance of graphene regarding the graphene sheet as the large-width limit of graphene strips in the ballistic limit. We find that the thermal conductance depends weakly on the direction angle $\theta$…

Materials Science · Physics 2009-05-22 Jin-Wu Jiang , Jian-Sheng Wang , Baowen Li

The infrared reflectance of the transition metal chalcogenide 1T-TaS2 has been measured at temperatures from 30K to 360K over 30-45,000cm^-1 (4meV-5.5eV). The optical conductivity was obtained by Kramers-Kronig analysis. At 360K only modest…

Condensed Matter · Physics 2013-10-31 L. V. Gasparov , K. G. Brown , A. C. Wint , D. B. Tanner , H. Berger , R. Gaal , L. Forro , G. Margaritondo

Fe3GeTe2 has emerged as one of the most fascinating van der Waals crystals due to its two-dimensional (2D) itinerant ferromagnetism, topological nodal lines and Kondo lattice behavior. However, lattice dynamics, chirality of phonons and…