Infrared spectroscopic study of phonons coupled to charge excitations in FeSi

Abstract

From an investigation of the optical conductivity of FeSi single crystals using FTIR spectroscopy in the frequency range from 30 to 20000 wavenumbers we conclude that the transverse effective charge of the Fe and Si ions is approximately 4e. Of the five optical phonons which are allowed by symmetry we observe only four, three of which have a Fano line shape presumably resulting from an interaction of these modes with the electronic continuum. We show that the large oscillator strength of the phonons results from a relatively weak coupling (lambda of the order of 0.1) of the lattice degrees of freedom to an electronic resonance above the semiconductor gap, which is also responsible for the large electronic polarizability of the medium.

Revtex, 10 pages, 2 postscript pictures, to be published in Phys. Rev. B Rapid Comm.

Cited by in corpus (40)

• Electrodynamics of Correlated Electron Materials
• Optical characterization of Bi${}_2$Se${}_3$ in a magnetic field: infrared evidence for magnetoelectric coupling in a topological insulator material
• Gate tunable charged-phonon effect in bilayer graphene
• Polarity-driven surface metallicity in SmB${}_6$
• Signatures of electronic correlations in iron silicide
• Optical conductivity of Bismuth-based topological insulator
• Effects of the magnetic orderings on the dynamical conductivity: optical investigations of EuFe${}_2$As${}_2$ single crystals
• Charged Magnons in NaV2O5
• Thermoelectricity in correlated narrow-gap semiconductors
• Polaronic conductivity in the photoinduced phase of 1T-TaS2
• Spin, Charge, and Bonding in Transition Metal Mono Silicides
• A possible mechanism for superconductivity in doped SrTiO3
• Optical investigation of the metal-insulator transition in $FeS{b}_2$
• Optical Properties of MFe_4P_12 filled skutterudites
• Temperature dependent correlations in covalent insulators
• Optical properties of BiTeBr and BiTeCl
• Electronic correlations in iron-pnictide superconductors and beyond; what can we learn from optics
• Optical spectroscopic study of the interplay of spin and charge in NaV2O5
• Infrared signatures of hole and spin stripes in La{2-x}Sr{x}CuO{4}
• Electron-phonon interaction and spectral weight transfer in Fe${}_{1-x}$Co${}_x$Si
• Optical conductivity of multifold fermions: the case of RhSi
• Electronic Structure Studies of FeSi: A Chiral Topological System
• Strong electron correlations in FeSb2: An optical investigation and comparison with RuSb2
• Enhancement of the electron-phonon scattering induced by intrinsic surface plasmon-phonon polaritons
• Phonon anomalies and electron-phonon interaction in RuSr_2GdCu_2O_8 ferromagnetic superconductor: Evidence from infrared conductivity
• Cooperative dynamics in doped manganite films: phonon anomalies in the ferromagnetic state
• Suppressed reflectivity due to spin-controlled localization in a magnetic semiconductor
• Probing FeSi, a d-electron topological Kondo insulator candidate, with magnetic field, pressure, and microwaves
• Evolution of ferroelectricity in tetrathiafulvalene-p-chloranil as a function of pressure and temperature
• Mott transition and collective charge pinning in electron doped Sr2IrO4
• Optical evidence for heavy charge carriers in FeGe
• Thermopower of the Correlated Narrow Gap Semiconductor FeSi and Comparison to RuSi
• From bad metal to Kondo insulator: temperature evolution of the optical properties of SmB${}_6$
• Electrodynamics of correlated electron systems
• A combined inelastic neutron scattering and \textit{ab initio} lattice dynamics study of FeSi
• Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa${}_3$
• Contribution of interband effects caused by long-wavelength transverse optical phonons to electron-phonon coupling in doped polar insulators
• Optical Properties of Iron-Selenide Na${}_{0.27}$K${}_{0.27}$Rb${}_{0.27}$Fe${}_{1.7}$Se${}_2$ Single Crystals
• Revealing electrically undetectable room temperature surface-mobility of bulky topological insulators by spectroscopic techniques
• Charge-localization-driven metal-insulator phase transition in layered molecular conductors