The Unexpected Properties of Alkali Metal Iron Selenide Superconductors

Abstract

The iron-based superconductors that contain FeAs layers as the fundamental building block in the crystal structures have been rationalized in the past using ideas based on the Fermi Surface nesting of hole and electron pockets when in the presence of weak Hubbard $U$ interactions. This approach seemed appropriate considering the small values of the magnetic moments in the parent compounds and the clear evidence based on photoemission experiments of the required electron and hole pockets. However, recent results in the context of alkali metal iron selenides, with generic chemical composition $A_x$Fe${}_{2-y}$Se${}_2$ ($A$ = alkali element), have drastically challenged those previous ideas since at particular compositions $y$ the low-temperature ground states are insulating and display antiferromagnetic magnetic order with large iron magnetic moments. Moreover, angle resolved photoemission studies have revealed the absence of hole pockets at the Fermi level in these materials. The present status of this exciting area of research, with the potential to alter conceptually our understanding of the iron-based superconductors, is here reviewed, covering both experimental and theoretical investigations. Other recent related developments are also briefly reviewed, such as the study of selenide two-leg ladders and the discovery of superconductivity in a single layer of FeSe. The conceptual issues considered established for the alkali metal iron selenides, as well as the several issues that still require further work, are discussed in the text.

By invitation for Rev. Mod. Physics; submitted to RMP in August 2012

References in corpus (60)

• High-temperature superconductivity in iron-based materials
• Strong electronic correlations from Hund's coupling
• Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-Doping
• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
• Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals
• Superconductivity at 32 K in single crystal Rb${}_{0.78}$Fe${}_2$Se${}_{1.78}$}
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
• d-wave pairing from spin fluctuations in the KxFe{2-y}Se2 superconductors
• Anisotropic Energy Gaps of Iron-based Superconductivity from Intra-band Quasiparticle Interference in LiFeAs
• Superconductivity at 32K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystals
• Structure and Magnetic Order in the NdFeAs(O,F) Superconductor System
• Transport properties of the new Fe-based superconductor KxFe2Se2 (Tc = 33 K)
• Strong nodeless pairing on separate electron Fermi surface sheets in (Tl, K)Fe${}_{1.78}$Se${}_2$ probed by ARPES
• Inter-pocket pairing and gap symmetry in Fe-based superconductors with only electron pockets
• Intrinsic phase separation in superconducting K0.8Fe1.6Se2 (Tc= 31.8 K) single crystals
• NMR Study in the Iron-Selenide Rb0.74Fe1.6Se2: Determination of the Superconducting Phase as Iron Vacancy-Free Rb0.3Fe2Se2
• Crossover from weak to strong pairing in unconventional superconductors
• Superconductivity and Magnetic Properties of high-quality single crystals of $A_x$Fe${}_2$Se${}_2$ ($A$ = K and Cs)
• Homogeneous vs. inhomogeneous coexistence of magnetic order and superconductivity probed by NMR in Co and K doped iron pnictides
• Iron vacancy superstructure and possible room temperature antiferromagnetic order in superconducting Cs_{y}Fe_{2-x}Se_2
• Ternary iron selenide K${}_{0.8}$Fe${}_{1.6}$Se${}_2$ is an antiferromagnetic semiconductor
• Atomic and electronic structures of FeSe monolayer and bilayer thin films on SrTiO${}_3$ (001): a first-principles study
• Neutron-Diffraction Measurements of an Antiferromagnetic Semiconducting Phase in the Vicinity of the High-Temperature Superconducting State of K${}_x$Fe${}_{2-y}$Se${}_2$
• Mott transition in Modulated Lattices and Parent Insulator of (K,Tl)yFexSe2 Superconductors
• Neutron and ARPES Constraints on the Couplings of the Multiorbital Hubbard Model for the Pnictides
• Angle-resolved photoemission evidence of s-wave superconducting gap in KxFe2-ySe2 superconductor
• 77Se NMR Investigation of the K(x)Fe(2-y)Se(2) High Tc Superconductor (Tc=33K)
• Emergence of Fully-Gapped $s_{++}$-wave and Nodal d-wave States Mediated by Orbital- and Spin-Fluctuations in Ten-Orbital Model for KFe${}_2$Se${}_2$
• Superconductivity at 44 K in K intercalated FeSe system with excess Fe
• Orbital differentiation and the role of orbital ordering in the magnetic state of Fe superconductors
• Magnetic States of the Two-Leg Ladder Alkali Metal Iron Selenides $A$Fe${}_2$Se${}_3$
• Stripes, spin resonance and $d_{x^2-y^2}-$pairing symmetry in FeSe-based layered superconductors
• Electronic and magnetic structures of ternary iron selenides AFe${}_2$Se${}_2$ (A=K, Cs, or Tl)
• From d-wave to s-wave pairing in the iron-pnictide superconductor (Ba,K)Fe2As2
• Competing Pairing Symmetries in a Generalized Two-Orbital Model for the Pnictides
• Spin glass behavior of insulating K0.8Fe2-xS2
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Electronic Structure, Topological Phase Transitions and Superconductivity in (K,Cs)xFe2Se2
• Conformity of spin fluctuations in alkali-metal iron selenide superconductors inferred from the observation of a magnetic resonant mode in K(x)Fe(2-y)Se(2)
• Crystal structure, physical properties and superconductivity in $A_x$Fe${}_2$Se${}_2$ single crystals
• Room temperature antiferromagnetic order in superconducting X_yFe_{2-x}Se_ 2, (X= Rb, K): a powder neutron diffraction study
• Observation of an isotropic superconducting gap at the Brillouin zone center of Tl${}_{0.63}$K${}_{0.37}$Fe${}_{1.78}$Se${}_2$
• Intrinsic crystal phase separation in antiferromagnetic superconductor RbyFe2-xSe2: a diffraction study
• Spin-wave excitations and superconducting resonant mode in Cs(x)Fe(2-y)Se2
• Spin reorientation in TlFe1.6Se2 with complete vacancy ordering
• Possible Superconducting Symmetry and Magnetic Correlations in K0.8Fe2Se2: A 77Se-NMR Study
• Coexistence of different electronic phases in the K0.8Fe1.6Se2 superconductor: a bulk-sensitive hard x-rays spectroscopy study
• Electronic Structure and Mott Localization in Iron Deficient TlFe${}_{1.5}$Se${}_2$ with Superstructures
• Macroscopic phase segregation in superconducting K0.73Fe1.67Se2 as seen by muon spin rotation and infrared spectroscopy
• Superconductivity and normal state properties of single-crystalline Tl0.47Rb0.34Fe1.63Se2 as seen via 77Se and 87Rb NMR
• Spin excitations in K${}_2$Fe${}_{4+x}$Se${}_5$: linear response approach
• Evolution of the nuclear and magnetic structures of TlFe1.6Se2 with temperature
• A direct probe of the variability of Coulomb correlation in Fe-pnictide superconductors
• Role of Fermi surface anisotropy in the study of gap anisotropy using magnetic-field-angle dependence of thermal oscillations in AyFe2-xSe2 superconductors
• Single nonmagnetic impurity resonance in FeSe-based 122-type superconductors as a probe for pairing symmetry
• Fermi surface evolution and checker-board block-spin antiferromagnetism in $A_x$Fe${}_{2-y}$Se${}_2$
• Doping-induced metallicity and coexistence of magnetic subsystems in {K${}_2$Fe${}_{4+x}$Se${}_5$}

Cited by in corpus (183)

• Multiferroic materials and magnetoelectric physics: symmetry, entanglement, excitation, and topology
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Ironing out the details of unconventional superconductivity
• Iron based high transition temperature superconductors
• Pressure-induced Superconductivity in the Iron-based Ladder Material BaFe2S3
• Common Electronic Origin of Superconductivity in (Li,Fe)OHFeSe Bulk Superconductor and Single-Layer FeSe/SrTiO3 Films
• Electronic structure, dimer physics, orbital-selective behavior, and magnetic tendencies in the bilayer nickelate superconductor La${}_3$Ni${}_2$O${}_7$ under pressure
• Electronic Structure and Superconductivity of FeSe-Related Superconductors
• High-Temperature Quantum Anomalous Hall Insulators in Lithium-Decorated Iron-Based Superconductor Materials
• Phase diagram of (Li1-xFex)OHFeSe: a bridge between iron selenide and arsenide superconductors
• Competition between charge-density-wave and superconductivity in the kagome metal RbV3Sb5
• Spin fluctuations in iron pnictides and chalcogenides: From antiferromagnetism to superconductivity
• BaFe${}_2$Se${}_3$: a high $T_{\mathrm{C}}$ magnetic multiferroic with large ferrielectric polarization
• The Nematic Energy Scale and the Missing Electron Pocket in FeSe
• Topological Phases in the Single-Layer FeSe
• Magnetic interactions in iron superconductors: A review
• Antiferromagnetic ground state with pair-checkboard order in FeSe
• Crystallographic, Electronic, Thermal and Magnetic Properties of Single-Crystal SrCo2As2
• High-temperature superconductivity in one-unit-cell FeSe films
• Block magnetic excitations in the orbitally selective Mott insulator BaFe2Se3
• Discrete superconducting phases in FeSe-derived superconductors
• Exotic magnetic order in the orbital-selective Mott regime of multiorbital systems
• Similarities and differences between nickelate and cuprate films grown on a SrTiO${}_3$ substrate
• Unified picture of the doping dependence of superconducting transition temperatures in alkali metal/ammonia intercalated FeSe
• Sequential structural and antiferromagnetic transitions in BaFe${}_2$Se${}_3$ under pressure
• Pressure-driven phase transition from antiferromagnetic semiconductor to nonmagnetic metal in two-leg ladders $A$Fe${}_2$$X$${}_3$ ($A$=Ba or K, $X$=S or Se)
• Distinguishing $s^{\pm }$ and $s^{++}$ electron pairing symmetries by neutron spin resonance in superconducting NaFe${}_{0.935}$Co${}_{0.045}$As
• Break-junction technique in application to layered superconductors (Review article)
• Unified phase diagram for iron-based superconductors
• Spin dynamics of the block orbital-selective Mott phase
• Ground state, collective mode, phase soliton and vortex in multiband superconductors
• Testing the Monte Carlo - Mean Field approximation in the one-band Hubbard model
• Optical conductivity of iron-based superconductors
• Magnetic properties and pairing tendencies of the iron-based superconducting ladder BaFe${}_2$S${}_3$: combined ab initio and density matrix renormalization group study
• Fingerprints of an Exotic Orbital-Selective Mott Phase in the Block Magnetic State of BaFe${}_2$Se${}_3$ Ladders
• Orbital selectivity in electron correlations and superconducting pairing of iron-based superconductors
• Spin fluctuations and superconductivity in KxFe{2-y}Se2
• Novel Magnetic Block States in Low-Dimensional Iron-Based Superconductors
• Vortex-line topology in iron-based superconductors with and without second-order topology
• Ab initio downfolding study of the iron-based ladder superconductor BaFe${}_2$S${}_3$
• Aspects of electron-phonon interactions with strong forward scattering in FeSe Thin Films on SrTiO${}_3$ substrates
• Structure of spin excitations in heavily electron-doped Li0.8Fe0.2ODFeSe superconductors
• Structure and composition of the superconducting phase in alkali iron selenide K${}_y$Fe${}_{1.6+x}$Se${}_2$
• First-principles study of magnetic properties in Fe-ladder compound BaFe2S3
• Thermoelectric properties of iron-based superconductors and parent compounds
• Percolative superconductivity in La2CuO4.06 by lattice granularity patterns with scanning micro X-ray absorption near edge structure
• Antiferromagnetism in trigonal SrMn2As2 and CaMn2As2 single crystals
• Topological Superconductivity in an s-wave Superconductor and Its Implication to Iron-based Superconductors
• Magnetic Lifshitz transition and its consequences in multi-band iron-based superconductors
• Topological Nonsymmorphic Crystalline Superconductors
• Peierls transition, ferroelectricity, and spin-singlet formation in the monolayer VOI${}_2$
• PdTe a 4.5K Type II BCS Superconductor
• Orbital-selective Peierls phase in the metallic dimerized chain MoOCl${}_2$
• The magnetic moment enigma in Fe-based high temperature superconductors
• Pairing Tendencies in a Two-orbital Hubbard Model in One Dimension
• Non-Fermi-liquid behaviors associated with a magnetic quantum-critical point in Sr(Co{1-x}Ni{x})2As2 single crystals
• Kinetic approach to superconductivity hidden behind a competing order
• The magnetic and electronic properties of Oxyselenides - influence of transition metal ions and lanthanides
• Collective modes in multiband superconductors: Raman scattering in iron selenides
• Enhanced moments of Eu in single crystals of the metallic helical antiferromagnet EuCo{2-y}As2
• Metallic behavior induced by potassium doping of the trigonal antiferromagnetic insulator EuMn2As2
• Gradual Enhancement of Stripe-Type Antiferromagnetism in Spin Ladder Material BaFe${}_2$S${}_3$ Under Pressure
• Iron telluride ladder compounds: Predicting the structural and magnetic properties of BaFe${}_2$Te${}_3$
• Understanding doping, vacancy, lattice stability and superconductivity in KxFe2-ySe2
• Three-dimensional Hubbard model in the thermodynamic limit
• Two types of superconducting domes in unconventional superconductors
• Parallelized Traveling Cluster Approximation to Study Numerically Spin-Fermion Models on Large Lattices
• Magnetic states of iron-based two-leg ladder tellurides
• Iron-based superconductors: teenage, complex, challenging
• Magnetic states of quasi-one-dimensional iron chalcogenide Ba${}_2$FeS${}_3$
• Transition from sign-reversed to sign-preserved Cooper-pairing symmetry in sulfur-doped iron selenide superconductors
• Electronic structure, magnetic properties, spin orientation, and doping effect in Mn${}_3$Si${}_2$Te${}_6$
• Origin of the Magnetic and Orbital ordering in $\alpha$-Sr${}_2$CrO${}_4$
• Spin fluctuations away from (pi,0) in the superconducting phase of molecular-intercalated FeSe
• Magnetic Phase Diagram of a Five-Orbital Hubbard Model in the Real-Space Hartree Fock Approximation Varying the Electronic Density
• Ferromagnetic cluster-glass phase in Ca(Co,Ir)2As2 crystals
• Emergence of Superconductivity in Doped Multiorbital Hubbard Chains
• Origin of Pressure-induced Superconducting Phase in K${}_x$Fe${}_{2-y}$Se${}_2$ studied by Synchrotron X-ray Diffraction and Spectroscopy
• Magnetic excitation spectra of strongly correlated quasi-one dimensional systems: Heisenberg versus Hubbard-like behavior
• Canted Antiferromagnetism in the Quasi-1D Iron Chalcogenide BaFe${}_2$Se${}_4$
• Magnetic states of the five-orbital Hubbard model for one-dimensional iron-based superconductors
• Two spatially separated phases in semiconducting Rb${}_{0.8}$Fe${}_{1.5}$S${}_2$
• Magnetic phase diagram of a two-orbital model for bilayer nickelates varying doping
• Itinerant G-type antiferromagnetic order in SrCr${}_2$As${}_2$
• Prediction of exotic magnetic states in the alkali metal quasi-one-dimensional iron selenide compound Na${}_2$FeSe${}_2$
• Ab-initio perspective on structural and electronic properties of iron-based superconductors
• Robust block magnetism in the spin ladder compound BaFe${}_2$Se${}_3$ under hydrostatic pressure
• Orbital-selective Mott phases of a one-dimensional three-orbital Hubbard model studied using computational techniques
• Neutron Scattering Measurements of Spatially Anisotropic Magnetic Exchange Interactions in Semiconducting K0.85Fe1.54Se2 (TN=280 K)
• Prediction of orbital selective Mott phases and block magnetic states in the quasi-one-dimensional iron chain Ce${}_2$O${}_2$FeSe${}_2$ under hole and electron doping
• Giant biquadratic interaction induced magnetic anisotropy in the iron-based superconductor AxFe2-ySe2
• Role of further-neighbor interactions in modulating the critical behavior of the Ising model with frustration
• Order parameter fluctuation and ordering competition in $\mathrm{B}{\mathrm{a}}_{1-\mathrm{x}}{\mathrm{K}}_{\mathrm{x}}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
• Disordered Fe vacancies and superconductivity in potassium-intercalated iron selenide (K2-xFe4+ySe5)
• Iron-based superconductors: tales from the nuclei
• Variational description of the ground state of the repulsive two-dimensional Hubbard model in terms of nonorthogonal symmetry-projected Slater determinants
• Anomalous Composition-Induced Crossover in the Magnetic Properties of the Itinerant-Electron Antiferromagnet Ca{1-x}Sr{x}Co{2-y}As{2}
• Stability of the novel interorbital-hopping mechanism for ferromagnetism in multi-orbital Hubbard models
• Spin resonance in AFe2Se2 with s-wave pairing symmetry
• Effective Exchange Interactions for Bad Metals and Implications for Iron-based Superconductors
• Magnetic correlations and pairing in the 1/5-depleted square lattice Hubbard model
• Exchange striction driven magnetodielectric effect and potential photovoltaic effect in polar CaOFeS
• Coexistence of intrinsic piezoelectricity, ferromagnetism and nontrivial band topology in Li-decorated Janus monolayer $\mathrm{F}{\mathrm{e}}_2\mathrm{SSe}$ with high Curie temperature
• Structural, electronic, and dynamical properties of the tetragonal and collapsed tetragonal phases of KFe${}_2$As${}_2$
• Origin of the Higher-$T_\rm{c}$ Phase in the K${}_x$Fe${}_{2-y}$Se${}_2$ System
• Strongly anisotropic electronic and magnetic structures in oxide dichlorides RuOCl${}_2$ and OsOCl${}_2$
• Mott localization in a pure stripe antiferromagnet Rb${}_{1-\delta }$Fe${}_{1.5-\sigma }$S${}_2$
• $B_{1g}$-like pairing states in two-leg ladder iron superconductors
• Electronic structure and nematic phase transition in superconducting multi-layer FeSe films grown by pulsed laser deposition method
• Stoichiometry and defect superstructures in epitaxial FeSe films on SrTiO3
• Phase competition in a one-dimensional three-orbital Hubbard-Holstein model
• Quantum Transitions of Nematic Phases in a Spin-$1$ Bilinear-Biquadratic Model and Their Implications for FeSe
• Possible Bicollinear Nematic State with Monoclinic Lattice Distortions in Iron Telluride Compounds
• Frustrated magnetic interactions in FeSe
• Spin Waves and Spatially Anisotropic Exchange Interactions in the $\mathrm{S}=2$ Stripe Antiferromagnet Rb${}_{0.8}$Fe${}_{1.5}$S${}_2$
• First Principles Study of the Magnetic Properties of LaOMnAs
• Multiple insulating phases due to the interplay of strong correlations and lattice geometry in a single-orbital Hubbard model
• Elucidating the magnetic and superconducting phases in the alkali metal intercalated iron chalcogenides
• High-pressure single-crystal neutron scattering study of magnetic and Fe vacancy orders in (Tl,Rb)2Fe4Se5 superconductor
• Phonon and magnetic dimer excitations in Fe-based S=2 spin ladder compound BaFe${}_2$Se${}_2$O
• Robustness of superconductivity to structural disorder in Sr${}_{0.3}$(NH${}_2$)${}_y$(NH${}_3$)${}_{1-y}$Fe${}_2$Se${}_2$
• Isotropic Quenched Disorder Triggers a Robust Nematic State in Electron-Doped Pnictides
• Role of the Extra-Fe in K2-xFe4+ySe5 superconductors
• Field-induced spin nematic Tomonaga-Luttinger liquid of the $S=1/2$ spin ladder system with the anisotropic ferromagnetic rung interaction
• Quasi-uniaxial pressure induced superconductivity in stoichiometric compound UTe${}_2$
• Dispersionless orbital excitations in (Li,Fe)OHFeSe superconductors
• Direct Observation of Microstructures on Superconducting Single Crystals of K${}_x$Fe${}_{2-y}$Se${}_2$
• Coexistence of localized and itinerant magnetism in intercalated iron-selenide (Li,Fe)OHFeSe
• Multi-reference symmetry-projected variational approximation for the ground state of the doped one-dimensional Hubbard model
• Possible Way to Make MgFeGe a New Fe-based Superconductor
• Structure, superconductivity, and magnetism in Rb1-xFe1.6Se2-zSz
• Oxygen adsorption induced superconductivity in ultrathin FeTe film on SrTiO3(001)
• Block antiferromagnetism and possible ferroelectricity in KFe${}_2$Se${}_2$
• Orbital Selective Directional Conductor in the Two Orbital Hubbard Model
• Optimal interlayer hopping and high temperature Bose-Einstein condensation of local pairs in quasi 2D superconductors
• Electronic Structure, Magnetic and Pairing Tendencies of Alternating Single-layer Bilayer Stacking Nickelate La${}_5$Ni${}_3$O${}_{11}$ Under Pressure
• Intertwined charge, spin, and pairing orders in doped iron ladders
• Spin correlation in trigonal EuMn${}_2$As${}_2$
• Electronic structure, magnetic properties and pairing tendencies of the copper-based honeycomb lattice Na${}_2$Cu${}_2$TeO${}_6$
• Evolution of the Pauli spin-paramagnetic effect on the upper critical fields of K${}_x$Fe${}_{2-y}$Se${}_{2-z}$S${}_z$ single crystals
• Orbital-selective correlations and renormalized electronic structure in LiFeAs
• Interplay between conducting and magnetic systems in the antiferromagnetic organic superconductor $\kappa$-(BETS)${}_2$FeBr${}_4$
• General trends of electronic structures, superconducting pairing, and magnetic correlations in the Ruddlesden-Popper nickelate $m$-layered superconductors La${}_{m+1}$Ni${}_m$O${}_{3m+1}$
• Phase transitions in a frustrated biquadratic Heisenberg model with coupled orbital degree of freedom for iron-based superconductors
• Pressure-induced superconductivity in iron-based spin-ladder compound BaFe2+δ(S1-Sex)3
• Electronic structure of ruthenium-doped iron chalcogenides
• Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides
• Incommensurate magnetic states induced by ordering competition in $\mathrm{B}{\mathrm{a}}_{1-\mathrm{x}}\mathrm{N}{\mathrm{a}}_{\mathrm{x}}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
• Connection between ambient-pressure and pressure-induced superconducting phases in alkaline iron selenide superconductors
• Impurity-induced sub-gap bound gap states in alkali doped iron chalcogenide superconductors
• Effect of the iron valence in the two types of layers in LiFeO${}_2$Fe${}_2$Se${}_2$
• Small influence of magnetic ordering on lattice dynamics in TaFe${}_{1.25}$Te${}_3$
• Luther-Emery liquid and dominant singlet superconductivity in the hole-doped Haldane spin-1 chain
• Superconductivity in Quantum Complex Matter: the Superstripes Landscape
• Phase-separation control of K${}_x$Fe${}_{2-y}$Se${}_2$ superconductor through rapid-quenching process
• Epitaxial stabilization of an orthorhombic Mg-Ti-O superconductor
• Nonmetallic Low-Temperature Normal State of K0.70Fe1.46Se1.85Te0.15
• Raman spectroscopy of K_xCo_{2-y}Se_2 single crystals near the ferromagnet-paramagnet transition
• Momentum distribution and non-Fermi liquid behaviour in low-doped two-orbital model: finite-size cluster quantum Monte Carlo approach
• Low-energy bound states at interfaces between superconducting and block antiferromagnet regions in KxFe{2-y}Se2
• Superconductivity from buckled-honeycomb-vacancy ordering
• Universal quasi-degenerate orbital origin of two-dome phases in iron pnictide superconductors
• Suppression of the antiferromagnetic order when approaching the superconducting state in a phase-separated crystal of K${}_x$Fe${}_{2-y}$Se${}_2$
• Interplay between nematic fluctuation and superconductivity in the two-orbital Hubbard model: A quantum Monte Carlo study
• Representation-protected topology of spin-singlet $s$-wave superconductors
• Slow in-plane magnetoresistance oscillations in multiband quasi-two-dimensional metals
• Study of non-Fermi Liquid behavior from partial nesting in multi-orbital superconductors
• Spin correlations in the parent phase of Li${}_{1-x}$Fe${}_x$ODFeSe
• Phonon Spectra in the Parent Superconducting Iron-tuned Telluride Fe${}_{1+x}$Te from Inelastic Neutron Scattering and Ab Initio Calculations
• Block Mott insulating state induced by next-nearest neighbor hopping in the S = 3/2 zigzag chain BaCoTe2O7
• Observation of Two Cascading Screening Processes in an Iron-based Superconductor
• Density Matrix Renormalization Group study of superconducting pairing near the quarter-filled Wigner crystal
• Emergent channel over a pair of pockets in strong density waves
• Detecting Crystallographic Lattice Chirality using Resonant Inelastic X-ray Scattering
• Vacancy Order and Physical Properties of a Ternary Compound Fe0.68Pd0.80Te with an α-Fe1+xTe-Type Structure
• What controls the superconducting dome of electron-doped FeSe?
• Coupled Hubbard ladders at weak coupling: Pairing and spin excitations
• Hot Electron-Driven Structural Expansion and Magnetic Collapse in Bilayer FeSe
• Numerical transfer matrix study of frustrated next-nearest-neighbor Ising models on square lattices
• Phase separation in iron chalcogenide superconductor Rb0.8+xFe1.6+ySe2 as seen by Raman light scattering and band structure calculations
• Intertwined charge, spin, and orbital degrees of freedom under electronic correlations in the one-dimensional Fe${}^{3+}$ chalcogenide chain