Magnetic Resonant Mode in the Low-Energy Spin-Excitation Spectrum of SuperconductingRb2Fe4Se5Single Crystals

2011/07/31 by J. T. Park, G. Friemel, Yuan Li +10 · 110 citations
Materials Science · Physics and Astronomy · #Atomic physics #Condensed matter physics #Energy (signal processing) #Inelastic neutron scattering #Iron-based superconductors research #Neutron scattering #Omega #Order (exchange) #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Rare-earth and actinide compounds #Scattering #Spin (aerodynamics) #Superconductivity #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevlett.107.177005

published in Physical Review Letters 107(17), 177005 (American Physical Society) · To be published in Phys. Rev. Lett. Figures and references have been updated in v2

arxiv created 2011/09/16 · openalex publication_date 2011/10/19 · arxiv updated 2015/03/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We have studied the low-energy spin-excitation spectrum of the single-crystalline Rb₂Fe₄Se₅ superconductor (T_c=32 K) by means of inelastic neutron scattering. In the superconducting state, we observe a magnetic resonant mode centered at an energy of \ensuremathℏ\ensuremathω_res=14 meV and at the (0.5 0.25 0.5) wave vector (unfolded Fe-sublattice notation), which differs from the ones characterizing magnetic resonant modes in other iron-based superconductors. Our finding suggests that the 245-iron selenides are unconventional superconductors with a sign-changing order parameter, in which bulk superconductivity coexists with the √(5)\ifmmode×\else\texttimes\fi√(5) magnetic superstructure. The estimated ratios of \ensuremathℏ\ensuremathω_res/k_BT_c\ensuremath≈5.1\ifmmode±\else\textpm\fi0.4 and \ensuremathℏ\ensuremathω_res/2\ensuremathΔ\ensuremath≈0.7\ifmmode±\else\textpm\fi0.1, where \ensuremathΔ is the superconducting gap, indicate moderate pairing strength in this compound, similar to that in optimally doped 1111 and 122 pnictides.

Citations

• A Novel Large Moment Antiferromagnetic Order in K 0.8 Fe 1.6 Se 2 Superconductor
• Two-dimensional resonant magnetic excitation inBaFe1.84Co0.16As2
• Block Spin Ground State and Three-Dimensionality of(K,Tl)yFe1.6Se2
• Emergence of fully gappeds++-wave and nodald-wave states mediated by orbital and spin fluctuations in a ten-orbital model of KFe2Se2
• The effect of collective spin-1 excitations on electronic spectra in high-Tcsuperconductors
• Nanoscale phase separation in the iron chalcogenide superconductor K<mml:mi/>0.8Fe<mml:mi/>1.6Se<mml:mi/>2as seen via scanning nanofocused x-ray diffraction
• Observation of Fermi-surface–dependent nodeless superconducting gaps in Ba 0.6 K 0.4 Fe 2 As 2
• Spin Gap and Resonance at the Nesting Wave Vector in SuperconductingFeSe0.4Te0.6
• Superconducting gap symmetry of Ba 0.6 K 0.4 Fe 2 As 2 studied by angle-resolved photoemission spectroscopy
• Electronic Phase Separation in the Slightly Underdoped Iron Pnictide SuperconductorBa1−xKxFe2As2

Cited by

• Exploration of new superconductors and functional materials, and fabrication of superconducting tapes and wires of iron pnictides
• Highly Anisotropic and Twofold Symmetric Superconducting Gap in Nematically OrderedFeSe0.93S0.07
• Spin resonances in iron selenide high-Tc superconductors by proximity to a hidden spin density wave