Superconductivity and electronic fluctuations in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ studied by Raman scattering

Abstract

Using polarization-resolved electronic Raman scattering we study under-doped, optimally-doped and over-doped Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ samples in the normal and superconducting states. We show that low-energy nematic fluctuations are universal for all studied doping range. In the superconducting state, we observe two distinct superconducting pair breaking peaks corresponding to one large and one small superconducting gaps. In addition, we detect a collective mode below the superconducting transition in the B${}_{2g}$ channel and determine the evolution of its binding energy with doping. Possible scenarios are proposed to explain the origin of the in-gap collective mode. In the superconducting state of the under-doped regime, we detect a re-entrance transition below which the spectral background changes and the collective mode vanishes.

arXiv comment11 pages, 6 figures

References in corpus (57)

• Nematic order in iron superconductors - who is in the driver's seat?
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Inelastic Light Scattering From Correlated Electrons
• Resonant Spin Excitation in the High Temperature Superconductor Ba0.6K0.4Fe2As2
• Pairing Symmetry and Pairing State in Ferropnictides: Theoretical Overview
• Quantum critical point lying beneath the superconducting dome in iron-pnictides
• Neutron Scattering from Magnetic Excitations in Bi_2 Sr_2 Ca_2 O_8+delta
• Effects of nematic fluctuations on the elastic properties of iron arsenide superconductors
• The effect of collective spin-1 excitations on electronic spectra in high-Tc superconductors
• Enhancement of superconductivity near a nematic quantum critical point
• Magnetic Resonant Mode in the Single-Layer High Temperature Superconductor Tl${}_2$Ba${}_2$Cu${}_{6+\delta }$
• Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopy
• The connection between superconducting phase correlations and spin excitations in YBa${}_2$Cu${}_3$O${}_{6.6}$: A magnetic field study
• Evidence for superconducting gap nodes in the zone-centered hole bands of KFe2As2 from magnetic penetration-depth measurements
• Multiple Nodeless Superconducting Gaps in (Ba0.6K0.4)Fe2As2 Superconductor from Angle-Resolved Photoemission Spectroscopy
• Observation of incipient charge nematicity in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Probing superconducting energy gap from infrared spectroscopy on a Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ single crystal with T${}_c$=37 K
• Universal heat conduction in the iron-arsenide superconductor KFe2As2 : Evidence of a d-wave state
• Pairing State with a time-reversal symmetry breaking in FeAs based superconductors
• Nematic susceptibility of hole- and electron-doped BaFe2As2 iron-based superconductors from shear modulus measurements
• Superconductivity-induced reentrance of orthorhombic distortion in Ba1-xKxFe2As2
• Low-energy microscopic models for iron-based superconductors: a review
• Possible Multiple Gap Superconductivity with Line Nodes in Heavily Hole-Doped Superconductor KFe2As2 Studied by 75As-NQR and Specific Heat
• Sign-reversal of the in-plane resistivity anisotropy in iron pnictides
• Sign-reversal of the in-plane resistivity anisotropy in hole-doped iron pnictides
• Distinct electronic nematicities between electron and hole underdoped iron pnictides
• Quasiparticle Heat Transport in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$: Evidence for a k-dependent Superconducting Gap without Nodes
• Universality of superconducting gaps in overdoped Ba0.3K0.7Fe2As2 observed by angle-resolved photoemission spectroscopy
• Fermi surface dichotomy of the superconducting gap and pseudogap in underdoped pnictides
• Critical Quadrupole Fluctuations and Collective Modes in Iron Pnictide Superconductors
• Observation of an Orbital Selective Electron-Mode Coupling in Fe-Based High-$T_c$ Superconductors
• Nematic fluctuations and the magneto-structural phase transition in $\mathrm{Ba}(\mathrm{F}{\mathrm{e}}_{1-\mathrm{x}}\mathrm{C}{\mathrm{o}}_{\mathrm{x}}{)}_2\mathrm{A}{\mathrm{s}}_2$
• Phonon anomalies in pure and underdoped R{1-x}K{x}Fe{2}As{2} (R = Ba, Sr) investigated by Raman light scattering
• Transport properties and asymmetric scattering in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ single crystals compared to the electron doped counterparts Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$}
• Effect of Fermi Surface Nesting on Resonant Spin Excitations in Ba1-xKxFe2As2
• Complex phase diagram of Ba${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$: a multitude of phases striving for the electronic entropy
• Evidence of a spin resonance mode in the iron-based superconductor Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ from scanning tunneling spectroscopy
• Raman-Scattering Detection of Nearly Degenerate $s$-Wave and $d$-Wave Pairing Channels in Iron-Based Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ and Rb${}_{0.8}$Fe${}_{1.6}$Se${}_2$ Superconductors
• Superconductivity in FeSe thin films driven by the interplay between nematic fluctuations and spin-orbit coupling
• Tetragonal magnetic phase in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ from x-ray and neutron diffraction
• A balancing act: Evidence for a strong subdominant d-wave pairing channel in $\mathrm{B}{\mathrm{a}}_{0.6}{\mathrm{K}}_{0.4}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
• Collective modes in superconductors with competing s- and d-wave interactions
• Theory of Raman response in a superconductor with extended s-wave symmetry: Application to Fe-pnictides
• Resonance in Optimally Electron-Doped Superconductor Nd${}_{1.85}$Ce${}_{0.15}$CuO${}_{4-\delta }$
• Antiferromagnetic Excitations and Van Hove Singularities in YBa${}_2$Cu${}_3$O${}_{6+x}$
• Nematic resonance in the Raman response of iron-based superconductors
• Collective $d-$wave Excitonic Modes in the Fe-Superconductors
• Theory of Raman scattering from Leggett's collective mode in a multiband superconductor: Application to MgB${}_2$
• Probing the pairing interaction and multiple Bardasis-Schrieffer modes using Raman spectroscopy
• Collective modes in multiband superconductors: Raman scattering in iron selenides
• Symmetry of re-entrant tetragonal phase in Ba1-xNaxFe2As2: Magnetic versus orbital ordering mechanism
• Eliashberg Analysis of Optical Spectra Reveals Strong Coupling of Charge Carriers to Spin Fluctuations in Superconducting Iron Pnictides
• Suppression of spin-exciton state in hole overdoped iron-based superconductors
• Raman resonance in iron-based superconductors: The magnetic scenario
• Superconductivity and fluctuation in Ba${}_{1-p}$K${}_p$Fe${}_2$As${}_2$ and Ba(Fe${}_{1-n}$Co${}_n$)${}_2$As${}_2$
• On the origin of the electronic anisotropy in iron pnicitde superconductors

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• Elastoresistance measurements on CaKFe${}_4$As${}_4$ and KCa${}_2$Fe${}_4$As${}_4$F${}_2$ with the Fe site of $C_{2v}$ symmetry
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• Growth of nematic susceptibility in the field-induced normal state of an iron-based superconductor revealed by elastoresistivity measurements in a 65 T pulsed magnet
• Superconductivity and phonon self-energy effects in Fe${}_{1+y}$Te${}_{0.6}$Se${}_{0.4}$
• The role of orbital nesting in the superconductivity of Iron-based Superconductors
• Quasiparticle scattering in a superconductor near a nematic critical point: resonance mode and multiple attractive channels
• Signatures of Bardasis-Schrieffer mode excitation in Third-Harmonic generated currents
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