Anisotropic optical properties of detwinned BaFe${}_2$As${}_2$

Abstract

The optical properties of a large, detwinned single crystal of BaFe${}_2$As${}_2$ have been examined over a wide frequency range above and below the structural and magnetic transition at $T_{\mathrm{N}}\simeq 138$ K. Above $T_{\mathrm{N}}$ the real part of the optical conductivity and the two infrared-active lattice modes are almost completely isotropic; the lattice modes show a weak polarization dependence just above $T_{\mathrm{N}}$. For $T<T_{\mathrm{N}}$, the optical conductivity due to the free-carrier response is anisotropic, being larger along the $a$ axis than the $b$ axis below $\simeq 30$ meV; above this energy the optical conductivity is dominated by the interband contributions, which appear to be isotropic. The splitting of the low-energy infrared-active mode below $T_{\mathrm{N}}$ is clearly observed, and the polarization modulation of the new modes may be used to estimate that the crystal is $\simeq 70$% detwinned. The high-frequency mode, with a threefold increase in strength of the lower branch below $T_{\mathrm{N}}$ and nearly silent upper branch, remains enigmatic.

arXiv comment8 pages with 5 figures and 1 table; expanded supplementary material

References in corpus (31)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Kinetic frustration and the nature of the magnetic and paramagnetic states in iron pnictides and iron chalcogenides
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• Effects of Co substitution on thermodynamic and transport properties and anisotropic $H_{c2}$ in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ single crystals
• Determination of the phase diagram of the electron doped superconductor Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Superconductivity up to 29 K in SrFe2As2 and BaFe2As2 at high pressures
• Superconductivity up to 30 K in the vicinity of quantum critical point in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Origin of the spin density wave instability in AFe${}_2$As${}_2$ (A=Ba, Sr) as revealed by optical spectroscopy
• Observation of Dirac Cone Electronic Dispersion in BaFe2As2
• In-plane electronic anisotropy of underdoped "122" Fe-arsenide superconductors revealed by measurements of detwinned single crystals
• Unprecedented anisotropic metallic state in BaFe2As2 revealed by optical spectroscopy
• Complete pressure dependent phase diagrams for SrFe2As2 and BaFe2As2
• Superconductivity coexisting with phase-separated static magnetic order in (Ba,K)Fe${}_2$As${}_2$, (Sr,Na)Fe${}_2$As${}_2$ and CaFe${}_2$As${}_2$
• Universal Decomposition of the Low-Frequency Conductivity Spectra of Iron-Pnictides Uncovering Fermi-Liquid Behavior
• Raman scattering study of (K${}_x$Sr${}_{1-x}$)Fe${}_2$As${}_2$ ($x$ = 0.0, 0.4)
• Phonon anomaly in BaFe2As2
• Evolution of bulk superconductivity in SrFe2As2 with Ni substitution
• Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFe${}_2$As${}_2$
• Spontaneous formation of a superconducting and antiferromagnetic hybrid state in SrFe2As2 under high pressure
• Origin of the resistive anisotropy in the electronic nematic phase of BaFe${}_2$As${}_2$ revealed by optical spectroscopy
• Dichotomy between in-plane magnetic susceptibility and resistivity anisotropies in extremely strained $BaF{e}_{2}A{s}_2$
• Structural properties and superconductivity of SrFe2As2-xPx and CaFe2As2-yPy
• Anisotropic in-plane optical conductivity in detwinned Ba(Fe1-xCox)2As2
• Phonon splitting and anomalous enhancement of infrared-active modes in BaFe${}_2$As${}_2$
• Charge dynamics of the spin-density-wave state in BaFe${}_2$As${}_2$
• Optical properties of $A$Fe${}_2$As${}_2$ ($A=$Ca, Sr, and Ba) single crystals
• Spectral weight transfer in strongly correlated Fe${}_{1.03}$Te
• Vibrational anomalies in AFe${}_2$As${}_2$ (A$=$Ca, Sr, and Ba) single crystals

Cited by in corpus (3)

• Broadband optical conductivity of the chiral multifold semimetal PdGa
• Anisotropic quasiparticle coherence in nematic BaFe${}_2$As${}_2$ studied with strain-dependent ARPES
• Spectral Evidence for Unidirectional Charge Density Wave in Detwinned BaNi${}_2$As${}_2$