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Related papers: Optic phonons and the soft mode in 2H-NbSe2

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We examine the effects of electron-phonon interaction on the dynamics of the charge carriers doped in two-dimensional (2D) Heisenberg antiferromagnet. The $t$-$J$ model Hamiltonian with a Fr\"ohlich term which couples the holes to a…

Condensed Matter · Physics 2009-10-28 B. Kyung , S. I. Mukhin , V. N. Kostur , R. A. Ferrell

Inelastic x-ray scattering and $ab$-$initio$ calculation are applied to investigate the lattice dynamics and electron-phonon coupling of the ternary silicide superconductor CaAlSi ($P/bar{6}m2$). A soft c-axis polarized mode is clearly…

Superconductivity · Physics 2009-11-13 S. Kuroiwa , A. Q. R. Baron , T. Muranaka , R. Heid , K. -P. Bohnen , J. Akimitsu

To clarify the origin of a charge-density wave (CDW) phase in 1$T$-TiSe$_2$, we study the ground state property of a half-filled two-band Hubbard model in a triangular lattice including electron-phonon interaction. By using the variational…

Strongly Correlated Electrons · Physics 2015-06-01 Hiroshi Watanabe , Kazuhiro Seki , Seiji Yunoki

We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB_2 and the isostructural AlB_2 within the framework of density functional perturbation theory using a mixed-basis…

Superconductivity · Physics 2009-11-07 K. -P. Bohnen , R. Heid , B. Renker

We investigate the dynamical effects of electron-phonon coupling (EPC) on the superconducting properties of two-dimensional (2D) systems, calculating the Eliashberg function in terms of dynamically renormalized phonons. By studying…

Superconductivity · Physics 2025-04-29 Juraj Krsnik , Dino Novko , Osor Slaven Barišić

Negative nonlinear electron-phonon coupling involving an infrared-active phonon mode can lead to an instability towards the formation of a polar lattice distortion with ferrielectric (FE) moments accompanied by an electronic charge-density…

Strongly Correlated Electrons · Physics 2018-10-30 M. Puviani , M. A. Sentef

We investigate the interplay between charge density wave (CDW) instabilities and ferromagnetism in SmNiC$_2$ using diffuse and inelastic x-ray scattering together with Raman spectroscopy. We identify a soft acoustic phonon driving the…

Temperature dependent inelastic neutron-scattering measurements of the generalized phonon density-of-states for superconducting MgCNi_3, T_c=8 K, give evidence for a soft-mode behavior of low-frequency Ni phonon modes. Results are compared…

Superconductivity · Physics 2009-11-10 R. Heid , B. Renker , H. Schober , P. Adelmann , D. Ernst , K. -P. Bohnen

We investigate the controversial case of charge-density-wave (CDW) order in single layer 1T-TiSe$_2$ by employing the density functional perturbation theory with on-site Hubbard interactions. The results emphasize the crucial role of…

Materials Science · Physics 2022-12-12 Dino Novko , Zahra Torbatian , Ivor Lončarić

We discuss the first theory for the depinning of low dimensional, incommensurate, charge density waves (CDWs) in the strong electron-phonon (e-p) regime. Arguing that most real CDWs systems invariably develop a gigantic dielectric constant…

Materials Science · Physics 2017-05-24 P. Quemerais

The pressure dependence of the critical temperature $T_c$ and upper critical field $H_{c2}(T)$ has been measured up to 19 GPa in the layered superconducting material 2H-NbSe$_2$. Relating the behavior of $H_{c2}(T)$ to Fermi surface…

Superconductivity · Physics 2009-11-11 H. Suderow , V. G. Tissen , J. P. Brison , J. L. Martinez , S. Vieira

The Fe pnictide parent compound EuFe2As2 exhibits a strongly momentum dependent carrier dynamics around the hole pocket at the center of the Brillouin zone. The very different dynamics of electrons and holes cannot be explained solely by…

We applied Time-Resolved Two-Photon Photoemission spectroscopy to probe the electron- phonon (e-ph) coupling strength in double-wall carbon nanotubes. The e-ph energy transfer rate G(Te,Tl) from the electronic system to the lattice depends…

Materials Science · Physics 2013-08-07 Ioannis Chatzakis

The Charge-density-wave(CDW) in 2H-NbSe2(TCDW ~ 33 K), which coexists with superconductivity(Tc = 7.2 K), is investigated using Angle-resolved photoemission spectroscopy as a function of temperature. Across TCDW, energy and momentum(k)…

Strongly Correlated Electrons · Physics 2007-05-23 T. Kiss , T. Yokoya , A. Chainani , S. Shin , T. Hanaguri , M. Nohara , H. Takagi

Interactions with electronic excitations can soften and/or broaden phonons. They are greatly amplified at wavevectors Q+- that connect parallel (nested) sheets of the Fermi surface. In such a case, called a Kohn anomaly, the phonon…

Strongly Correlated Electrons · Physics 2009-09-04 D. Lamago , M. Hoesch , M. Krisch , R. Heid , K. -P. Bohnen , P. Boeni , D. Reznik

In this paper, we investigate the electronic band structure, lattice dynamics and electron-phonon interaction in $\delta$-NbN, $\varepsilon$-NbN and WC-NbN by performing systematic ab initio calculations based on DFT-GGA. The calculated…

Superconductivity · Physics 2019-03-27 K. Ramesh Babu , Guang-Yu Guo

We present a Raman scattering study of Ca$_2$RuO$_4$, in which we investigate the temperature-dependence of the lattice dynamics and the electron-phonon interaction below the metal-insulator transition temperature ({\it T}$_{\rm MI}$).…

Strongly Correlated Electrons · Physics 2009-11-11 H. Rho , S. L. Cooper , S. Nakatsuji , H. Fukazawa , Y. Maeno

Radio-frequency compressed ultrafast electron diffraction has been used to probe the coherent and incoherent coupling of impulsive electronic excitation at 1.55 eV (800 nm) to optical and acoustic phonon modes directly from the perspective…

Materials Science · Physics 2015-06-23 Robert P. Chatelain , Vance R. Morrison , Bart L. M. Klarenaar , Bradley J. Siwick

Charge-density-wave (CDW) order and superconductivity often compete in low-dimensional materials, yet their interplay in Janus MXenes remains largely unexplored. Here, we present a comprehensive first-principles investigation of the…

Superconductivity · Physics 2026-03-09 Jakkapat Seeyangnok , Udomsilp Pinsook , Graeme J Ackland

The phonon-mode decomposition of the electron-phonon coupling in the MgB2-like system Li_{1-x}BC is explored using first principles calculations. It is found that the high temperature superconductivity of such systems results from extremely…

Superconductivity · Physics 2009-11-07 J. M. An , S. Y. Savrasov , H. Rosner , W. E. Pickett
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