Critical Quadrupole Fluctuations and Collective Modes in Iron Pnictide Superconductors

Abstract

The multiband nature of iron pnictides gives rise to a rich temperature-doping phase diagram of competing orders and a plethora of collective phenomena. At low dopings, the tetragonal-to-orthorhombic structural transition is closely followed by a spin density wave transition both being in close proximity to the superconducting phase. A key question is the nature of high-$T_c$ superconductivity and its relation to orbital ordering and magnetism. Here we study the NaFe${}_{1-x}$Co${}_x$As superconductor using polarization-resolved Raman spectroscopy. The Raman susceptibility displays critical enhancement of non-symmetric charge fluctuations across the entire phase diagram which are precursors to a $d$-wave Pomeranchuk instability at temperature $θ(\mbox{x})$. The charge fluctuations are interpreted in terms of quadrupole inter-orbital excitations in which the electron and hole Fermi surfaces breathe in-phase. Below $T_c$, the critical fluctuations acquire coherence and undergo a metamorphosis into a coherent ingap mode of extraordinary strength.

21 pages, 15 figures. To appear in Phys. Rev. B

References in corpus (44)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• High-temperature superconductivity in iron-based materials
• Quantum Criticality in Heavy Fermion Metals
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Theory of Electron Nematic Order in LaOFeAs
• Inelastic Light Scattering From Correlated Electrons
• Ising and Spin orders in Iron-based Superconductors
• Quantum phase transitions of metals in two spatial dimensions: II. Spin density wave order
• Orbital-driven nematicity in FeSe
• Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors
• A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study
• Enhancement of superconductivity near a nematic quantum critical point
• Are non-Fermi-liquids stable to Cooper pairing?
• Origin of the spin density wave instability in AFe${}_2$As${}_2$ (A=Ba, Sr) as revealed by optical spectroscopy
• Origin of the tetragonal-to-orthorhombic (nematic) phase transition in FeSe: a combined thermodynamic and NMR study
• Fermi liquid instabilities in the spin channel
• Orbital Order and Spontaneous Orthorhombicity in Iron Pnictides
• Self-Consistent Vertex Correction Analysis for Iron-Based Superconductors: Mechanism of Coulomb-Interaction-Driven Orbital Fluctuations
• Quasiparticle mass enhancement approaching optimal doping in a high-Tc superconductor
• Nematic spin correlations in the tetragonal state of uniaxial strained BaFe2-xNixAs2
• Observation of Leggett's collective mode in a multi-band MgB2 superconductor
• Evolution of the optical spectrum with doping in iron pnictides Ba(Fe1-xCox)2As2
• The origin of nematic order in FeSe
• Electronic nematic susceptibility of iron-based superconductors
• Phase Diagram and Calorimetric Properties of NaFe${}_{1-x}$Co${}_x$As
• Infrared Measurement of the Pseudogap in P-Doped and Co-Doped BaFe2As2 High-Temperature Superconductors
• Structural and magnetic phase transitions near optimal superconductivity in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Anisotropic but nodeless superconducting gap in the presence of spin density wave in iron-pnictide superconductor NaFe1-xCoxAs
• A balancing act: Evidence for a strong subdominant d-wave pairing channel in $\mathrm{B}{\mathrm{a}}_{0.6}{\mathrm{K}}_{0.4}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
• Theory of Raman response in a superconductor with extended s-wave symmetry: Application to Fe-pnictides
• Evolution from unconventional spin density wave to superconductivity and a novel gap-like phase in NaFe1-xCoxAs
• Nematic resonance in the Raman response of iron-based superconductors
• Quantum critical point shifts under superconductivity: the pnictides and the cuprates
• Theory of Raman scattering from Leggett's collective mode in a multiband superconductor: Application to MgB${}_2$
• Similar zone-center gaps in the low-energy spin-wave spectra of NaFeAs and BaFe2As2
• Manifestation of nematic degrees of freedom in the Raman response function of iron pnictides
• Collective modes in multiband superconductors: Raman scattering in iron selenides
• Raman scattering as a probe of nematic correlations
• Crystal growth and the electronic phase diagram of the 4$d$ doped Na${}_{1-\delta }$Fe${}_{1-x}$Rh${}_x$As in comparison with 3$d$ doped Na${}_{1-\delta }$Fe${}_{1-x}$Co${}_x$As
• Raman resonance in iron-based superconductors: The magnetic scenario
• Simultaneous Vanishing of the Nematic Electronic State and the Structural Orthorhombicity in NaFe${}_{1-x}$Co${}_x$As Single Crystals
• Non-Fermi Liquid behavior at the Orbital Ordering Quantum Critical Point in the Two-Orbital Model

Cited by in corpus (68)

• High Temperature Superconductivity in Iron Pnictides and Chalcogenides
• Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
• Ironing out the details of unconventional superconductivity
• Superconductivity and non-Fermi liquid behavior near a nematic quantum critical point
• Magnetism, superconductivity, and spontaneous orbital order in iron-based superconductors: who comes first and why?
• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Ising nematic quantum critical point in a metal: a Monte Carlo study
• Orbital-dependent Fermi Surface shrinking as a fingerprint of nematicity in FeSe
• Charge induced nematicity in FeSe
• Monte Carlo Studies of Quantum Critical Metals
• Nematic Fluctuations in the Cuprate Superconductor Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$
• Unified phase diagram for iron-based superconductors
• Elastic coupling and spin-driven nematicity in iron-based superconductors
• Observation of superconducting collective modes from competing pairing instabilities in single-layer NbSe${}_2$
• Interplay between magnetism, superconductivity, and orbital order in a 5-pocket model for iron-based superconductors - a parquet renormalization group study
• Pairing Mechanism in Hunds Metal Superconductors and the Universality of the Superconducting Gap to Critical Temperature Ratio
• NMR evidence for inhomogeneous nematic fluctuations in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Nematic quantum criticality in an Fe-based superconductor revealed by strain-tuning
• Competing instabilities, orbital ordering and splitting of band degeneracies from a parquet renormalization group analysis of a 4-pocket model for iron-based superconductors: application to FeSe
• Nematic Quantum Critical Fluctuations in BaFe${}_{2-x}$Ni${}_x$As${}_2$
• Probing the pairing interaction and multiple Bardasis-Schrieffer modes using Raman spectroscopy
• Electron Mass Enhancement near a Nematic Quantum Critical Point in NaFe${}_{1-x}$Co${}_x$As
• Dynamical susceptibility near a long-wavelength critical point with a nonconserved order parameter
• Superconductivity-induced nematicity
• Conservation laws, vertex corrections, and screening in Raman spectroscopy
• Effect of nematic order on the low-energy spin fluctuations in detwinned BaFe${}_{1.935}$Ni${}_{0.065}$As${}_2$
• Superconductivity and electronic fluctuations in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ studied by Raman scattering
• Interplay of lattice, electronic and spin degrees of freedom in detwinned BaFe${}_2$As${}_2$: a Raman scattering study
• Nematic correlation length in iron-based superconductors probed by inelastic x-ray scattering
• High Tc superconductivity in CaKFe${}_4$As${}_4$ in absence of nematic fluctuations
• Lattice-Shifted Nematic Quantum Critical Point in FeSe${}_{1-x}$S${}_x$
• Subdominant $d$-wave interaction in superconducting CaKFe${}_4$As${}_2$?
• Local nematic susceptibility in stressed BaFe${}_2$As${}_2$ from NMR electric field gradient measurements
• Raman response in the nematic phase of FeSe
• Elastoresistance measurements on CaKFe${}_4$As${}_4$ and KCa${}_2$Fe${}_4$As${}_4$F${}_2$ with the Fe site of $C_{2v}$ symmetry
• Raman Study of Cooper Pairing Instabilities in (Li${}_{1-x}$Fe${}_x$)OHFeSe
• Measurement of Elastoresistivity at Finite Frequency by Amplitude Demodulation
• Raman scattering study of spin-density-wave-induced anisotropic electronic properties in AFe2As2 (A=Ca,Eu)
• Nematic Fluctuations and Phase Transitions in LaFeAsO: a Raman Scattering Study
• Dynamical susceptibility of a near-critical non-conserved order parameter and B2g Raman response in Fe-based superconductors
• Lattice dynamics, crystal-field excitations and quadrupolar fluctuations of YbRu${}_2$Ge${}_2$
• Fluctuations and pairing in Fe-based superconductors: Light scattering experiments
• Multipole-fluctuation pairing mechanism of $d_{x^2-y^2}+ig$ superconductivity in Sr${}_2$RuO${}_4$
• Quadrupolar charge dynamics in the nonmagnetic FeSe${}_{1-x}$S${}_x$ superconductors
• Theoretical insights into electronic nematic order, bond-charge orders, and plasmons in cuprate superconductors
• Stress-induced nematicity in EuFe2As2 studied by phononic Raman spectroscopy
• Superconductivity and fluctuation in Ba${}_{1-p}$K${}_p$Fe${}_2$As${}_2$ and Ba(Fe${}_{1-n}$Co${}_n$)${}_2$As${}_2$
• Fluctuation Spectrum of Critical Fermi Surfaces
• Nonlinear uniaxial pressure dependence of $T_c$ in iron-based superconductors
• Colossal transverse magnetoresistance due to nematic superconducting phase fluctuations in a copper oxide
• The Hidden Nematic Fluctuations in the Triclinic (Ca0.85La0.15)10(Pt3As8)(Fe2As2)5 Superconductor Revealed by Ultrafast Optical Spectroscopy
• Magneto-elastic coupling in Fe-based superconductors
• Quantum critical fluctuations in an Fe-based superconductor
• Doping evolution of the gap structure and spin-fluctuation pairing in $Ba(F{e}_{1-x}C{o}_x{)}_{2}A{s}_2$ superconductors
• Electronic Raman response of a superconductor across a time reversal symmetry breaking phase transition
• Superconducting gap and nematic resonance at the quantum critical point observed by Raman scattering in $\mathrm{BaF}{\mathrm{e}}_2({\mathrm{As}}_{1-x}{\mathrm{P}}_x{)}_2$
• Variation of shear moduli across superconducting phase transitions
• Theories for charge-driven nematicity in kagome metals
• Nematic fluctuations in the non-superconducting iron pnictide BaFe${}_{1.9-x}$Ni${}_{0.1}$Cr${}_x$As${}_2$
• Superconductivity and phonon self-energy effects in Fe${}_{1+y}$Te${}_{0.6}$Se${}_{0.4}$
• Possible signature of broken symmetry state near the quantum critical point in P doped BaFe${}_2$As${}_2$: A Raman spectroscopy study
• Measuring the imaginary time dynamics of quantum materials
• Nematic fluctuations mediated superconductivity revealed by anisotropic strain in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Elasto-Raman scattering: arsenic optical phonon as a probe of nematicity in BaFe${}_2$As${}_2$
• Quasiparticle scattering in a superconductor near a nematic critical point: resonance mode and multiple attractive channels
• Divergence of the quadrupole-strain susceptibility of YbRu${}_2$Ge${}_2$; a local moment realization of electronic nematicity
• Phase separation in iron chalcogenide superconductor Rb0.8+xFe1.6+ySe2 as seen by Raman light scattering and band structure calculations
• Detecting isotropic density and nematic fluctuations using ultrafast coherent phonon spectroscopy