Superconductivity by Hidden Spin Fluctuations in Electron-Doped Iron Selenide

Abstract

Berg, Metlitski and Sachdev, Science 338, 1606 (2012), have shown that the exchange of hidden spin fluctuations by conduction electrons with two orbitals can result in high-temperature superconductivity in copper-oxide materials. We introduce a similar model for high-temperature iron-selenide superconductors that are electron doped. Conduction electrons carry the minimal 3d xz and 3d yz iron-atom orbitals. Low-energy hidden spin fluctuations at the checkerboard wavevector Q_AF result from nested Fermi surfaces at the center and at the corner of the unfolded (one-iron) Brillouin zone. Magnetic frustration from super-exchange interactions via the selenium atoms stabilize hidden spin fluctuations at Q_AF versus true spin fluctuations. At half filling, Eliashberg theory based purely on the exchange of hidden spin fluctuations reveals a Lifshitz transition to electron/hole Fermi surface pockets at the corner of the folded (two-iron) Brillouin zone, but with vanishing spectral weights. The underlying hidden spin-density wave groundstate is therefore a Mott insulator. Upon electron doping, Eliashberg theory finds that the spectral weights of the hole Fermi surface pockets remain vanishingly small, while the spectral weights of the larger electron Fermi surface pockets become appreciable. This prediction is therefore consistent with the observation of electron Fermi surface pockets alone in electron-doped iron selenide by angle-resolved photoemission spectroscopy (ARPES). Eliashberg theory also finds an instability to S+- superconductivity at electron doping, with isotropic Cooper pairs that alternate in sign between the visible electron Fermi surface pockets and the faint hole Fermi surface pockets. Comparison with the isotropic energy gaps observed in electron-doped iron selenide by ARPES and by scanning tunneling microscopy (STM) is consistent with short-range hidden magnetic order.

arXiv comment48 pages, 7 figures, plus supplemental material (11 pages, 4 figures)

References in corpus (45)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3
• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3
• Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor
• A minimal two-band model for the superconducting Fe-pnictides
• Ising and Spin orders in Iron-based Superconductors
• Direct observation of high temperature superconductivity in one-unit-cell FeSe films
• Band Structure and Fermi Surface of an Extremely Overdoped Iron-Based Superconductor KFe2As2
• Spin-triplet p-wave pairing in a 3-orbital model for iron pnictide superconductors
• Common Electronic Origin of Superconductivity in (Li,Fe)OHFeSe Bulk Superconductor and Single-Layer FeSe/SrTiO3 Films
• Observation of universal strong orbital-dependent correlation effects in iron chalcogenides
• d-wave pairing from spin fluctuations in the KxFe{2-y}Se2 superconductors
• Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3(110)
• Plain s-wave superconductivity in single-layer FeSe on SrTiO3 probed by scanning tunneling microscopy
• Sign-problem-free quantum Monte Carlo of the onset of antiferromagnetism in metals
• Orbital-selective Mott Phase in Multiorbital Models for Alkaline Iron Selenides K(1-x)Fe(2-y)Se2
• The Electron Pairing of K${}_x$Fe${}_{2-y}$Se${}_2$
• Model for the Magnetic Order and Pairing Channels in Fe Pnictide Superconductors
• Enhanced superconductivity and evidence for novel pairing in single-layer FeSe on SrTiO3 thin film under large tensile strain
• Inter-pocket pairing and gap symmetry in Fe-based superconductors with only electron pockets
• Surface electronic structure and isotropic superconducting gap in (Li${}_{0.8}$Fe${}_{0.2}$)OHFeSe
• Properties of a two orbital model for oxypnictide superconductors: Magnetic order, B_2g spin-singlet pairing channel, and its nodal structure
• Symmetry analysis of possible superconducting states in KxFe2Se2 superconductors
• Interband superconductivity: contrasts between BCS and Eliashberg theory
• Angle-resolved photoemission evidence of s-wave superconducting gap in KxFe2-ySe2 superconductor
• High Tc via spin fluctuations from incipient bands: application to monolayers and intercalates of FeSe
• 77Se NMR study of pairing symmetry and spin dynamics in KyFe2-xSe2
• Resilient nodeless $d$-wave superconductivity in monolayer FeSe
• Three-band s+- Eliashberg theory and the superconducting gaps of iron pnictides
• Superconductivity in FeSe thin films driven by the interplay between nematic fluctuations and spin-orbit coupling
• Surface electronic structure and evidence of plain s-wave superconductivity in (Li0.8Fe0.2)OHFeSe
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Spectroscopic and thermodynamic properties in a four-band model for pnictides
• Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xKxFe2As2 (0.2 < x < 1.0) series
• Structure of spin excitations in heavily electron-doped Li0.8Fe0.2ODFeSe superconductors
• Classification of Symmetry Derived Pairing at M Point in FeSe
• Heat capacity jump at T_c and pressure derivatives of superconducting transition temperature in the Ba(1-x)NaxFe2As2 (0.1 <= x <= 0.9) series
• Magnetic excitations in ferro-pnictide materials controlled by a quantum critical point into hidden order
• Emergent Nesting of the Fermi Surface from Local-Moment Description of Iron-Pnictide High-Tc Superconductors
• Fermi surface pockets in electron-doped iron superconductor by Lifshitz transition
• Spin Resonances in Iron-Selenide High-Tc Superconductors by Proximity to Hidden Spin Density Wave
• Isotropic Cooper Pairs with Emergent Sign Changes in Single-Layer Iron Superconductor

Cited by in corpus (6)

• Multidome superconductivity in charge density wave kagome metals
• Spin Resonances in Iron-Selenide High-Tc Superconductors by Proximity to Hidden Spin Density Wave
• Enhanced superconductivity and moderate spin fluctuations suppressed at low energies in heavily electron-doped La1111-based superconductor
• Robust $s_{\pm }$-wave pairing in a bilayer two-orbital model of pressurized La${}_3$Ni${}_2$O${}_7$ without the $\gamma$ Fermi surface
• Editorial on Research Topic: High-Tc Superconductivity in Electron-Doped Iron Selenide and Related Compounds
• Quantum-Critical Spin-Density Waves in Iron-Selenide High-Tc Superconductors