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Related papers: Fluctuation-enhanced electron-phonon coupling in F…

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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…

Strongly Correlated Electrons · Physics 2012-05-01 Pradeep Kumar , A. Bera , D. V. S. Muthu , S. N. Shirodkar , R. Saha , A. Shireen , A. Sundaresan , U. V. Waghmare , A. K. Sood , C. N. R. Rao

The sequence of phase transitions in PbHf0.83Sn0.17O3 has been studied by THz, far infrared and Raman spectroscopies, revealing the complementary behaviour of both, polar and non-polar phonons and their impact on the transition lattice…

We report comprehensive Raman-scattering measurements on a single crystal of double-perovskite Nd2ZnIrO6 in temperature range of 4-330 K, and spanning a broad spectral range from 20 cm-1 to 5500 cm-1. The paper focuses on lattice vibrations…

Strongly Correlated Electrons · Physics 2020-05-20 Birender Singh , M. Vogl , S. Wurmehl , S. Aswartham , B. Büchner , Pradeep Kumar

We report a comprehensive Raman study of the phonon behaviour in PdSe$_2$ in the temperature range of 5 K to 300 K. A remarkable change in the Raman spectrum is observed at 120 K: a significant enhancement of the out-of-plane phonon…

We report plane-polarized Raman scattering spectra of iron oxypnictide superconductor NdFeAsO$_{1-x}$F$_x$ single crystals with varying fluorine $x$ content. The spectra exhibit sharp and symmetrical phonon lines with a weak dependence on…

Superconductivity · Physics 2009-11-13 Y. Gallais , A. Sacuto , M. Cazayous , P. Cheng , L. Fang , H. H. Wen

Phase transitions with lowering temperature is a manifestation of decreased entropy and within the Landau theoretical framework these are accompanied by the symmetry breaking. Whenever a symmetry is broken weakly or strongly, it leaves its…

Strongly Correlated Electrons · Physics 2023-12-12 Atul G. Chakkar , Deepu Kumar , Pradeep Kumar

Heavily electron-doped and single-layer FeSe superconduct at much higher temperatures than bulk FeSe. There have been a number of proposals attempting to explain the origin of the enhanced transition temperature, including the proximity to…

Superconductivity · Physics 2018-04-12 Wen Huang , Manfred Sigrist , Zheng-Yu Weng

We investigate the effects of electron-phonon coupling, as well as of spin and charge fluctuations on the superconducting state in a single layer of FeSe on SrTiO$_3$ substrate. These three bosonic mediators of Cooper pairing are treated on…

Superconductivity · Physics 2020-11-11 Fabian Schrodi , Alex Aperis , Peter Oppeneer

Selective excitation of coherent high-amplitude vibrations of atoms in a solid can induce exotic nonequilibrium states, in which the character of interactions between electronic, magnetic and lattice degrees of freedom is considerably…

Materials Science · Physics 2020-12-08 A. A. Melnikov , Yu. G. Selivanov , S. V. Chekalin

[Fe(phen)2(NCS)2] is a prototype transition metal complex material, which undergoes a phase transition between low-spin (LS) and high-spin (HS) phases, induced by temperature, pressure or light. Vibrational modes play a key role for…

Inelastic neutron scattering measurements on the molecular dimer-Mott insulator $\kappa$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl reveal a phonon anomaly in a wide temperature range. Starting from $T_{\rm ins}\sim50$-$60$ K where the charge gap…

The superconducting critical temperature, $T_{\rm c}$, of FeSe can be dramatically enhanced by intercalation of a molecular spacer layer. Here we report on a $^{77}$Se, $^7$Li and $^1$H nuclear magnetic resonance (NMR) study of the powdered…

We investigate the excitation of phonons in photoexcited antimony and demonstrate that the entire electron-lattice interactions, in particular coherent and incoherent electron-phonon coupling, can be probed simultaneously. Using femtosecond…

A first-principles-based method for computing phonons of magnetic random solid solutions including thermal magnetic fluctuations is developed. The method takes fluctuations of force constants (FCs) due to magnetic excitations as well as due…

Materials Science · Physics 2019-08-07 Yuji Ikeda , Fritz Körmann , Biswanath Dutta , Abel Carreras , Atsuto Seko , Jörg Neugebauer , Isao Tanaka

Raman scattering spectra of zigzag spin chain TaFe$_{1.25}$Te$_3$ single crystal are presented in a temperature range from 80 to 300 K. Nine Raman active modes of $A_g$ and $B_g$ symmetry are clearly observed and assigned by probing…

Phonons in single crystals of PrFeAsO_{1-y} are investigated using high-resolution inelastic x-ray scattering and ab initio pseudopotential calculations. Extensive measurements of several samples at temperatures spanning the magnetic…

Strongly Correlated Electrons · Physics 2011-08-12 T. Fukuda , A. Q. R. Baron , H. Nakamura , S. Shamoto , M. Ishikado , M. Machida , H. Uchiyama , A. Iyo , H. Kito , J. Mizuki , M. Arai , H. Eisaki

Lattice and spin excitations have been studied by Raman scattering in hexagonal YbMnO3 single crystals. The temperature dependences of the phonon modes show that the E2 mode at 256 cm-1 related to the displacement of Mn and O ions in a-b…

Strongly Correlated Electrons · Physics 2012-11-12 J. Liu , C. Toulouse , P. Rovillain , M. Cazayous , Y. Gallais , M. -A. Measson , S. W. Cheong , N. Lee , A. Sacuto

We investigated long-wavelength nematic fluctuations in an Fe-based superconductor LiFeAs near q=(0.05,0,0) by measuring temperature-dependent renormalization of acoustic phonons through inelastic neutron scattering. We found that the…

Superconductivity · Physics 2016-11-10 Adrian Merritt , Jose Rodriguez-Rivera , Yu Li , Weiyi Wang , Chenglin Zhang , Pengcheng Dai , Dmitry Rezik

The anisotropic spin glass transition, in which spin freezing is observed only along the c-axis in pseudobrookite Fe$_2$TiO$_5$, has long been perplexing because the Fe$^{3+}$ moments (d$^5$) are expected to be isotropic. Recently, neutron…

Disordered Systems and Neural Networks · Physics 2023-01-18 Yu Li , P. G. LaBarre , D. M. Pajerowski , A. P. Ramirez , S. Rosenkranz , D. Phelan

Interactions between electrons and lattice vibrations are responsible for a wide range of material properties and applications. Recently, there has been considerable interest in the development of resonant inelastic x-ray scattering (RIXS)…