On the Remarkable Superconductivity of FeSe and its Close Cousins

Abstract

Emergent electronic phenomena in iron-based superconductors have been at the forefront of condensed matter physics for more than a decade. Much has been learned about the origin and intertwined roles of ordered phases, including nematicity, magnetism, and superconductivity, in this fascinating class of materials. In recent years, focus has been centered on the peculiar and highly unusual properties of FeSe and its close cousins. This family of materials has attracted considerable attention due to the discovery of unexpected superconducting gap structures, a wide range of superconducting critical temperatures, and evidence for nontrivial band topology, including associated spin-helical surface states and vortex-induced Majorana bound states. Here, we review superconductivity in iron chalcogenide superconductors, including bulk FeSe, doped bulk FeSe, FeTe${}_{1-x}$Se${}_x$, intercalated FeSe materials, and monolayer FeSe and FeTe${}_{1-x}$Se${}_x$ on SrTiO${}_3$. We focus on the superconducting properties, including a survey of the relevant experimental studies, and a discussion of the different proposed theoretical pairing scenarios. In the last part of the paper, we review the growing recent evidence for nontrivial topological effects in FeSe-related materials, focusing again on interesting implications for superconductivity.

review article, 57 pages, 23 figures

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Cited by in corpus (79)

• Ironing out the details of unconventional superconductivity
• Exotic Superconducting States in FeSe-based Materials
• Probing topological quantum matter with scanning tunnelling microscopy
• Theory of Cross Phenomena and Their Coefficients Beyond Onsager Theorem
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• Multiflavor Mott insulators in quantum materials and ultracold atoms
• Topological Superconductivity Induced by Magnetic Texture Crystals
• Odd-parity Magnetism Driven by Antiferromagnetic Exchange
• Quantum noise spectroscopy of dynamical critical phenomena
• Antiferromagnetism in two-dimensional materials: progress and computational challenges
• Non-local $d_{xy}$ nematicity and the missing electron pocket in FeSe
• Enhanced superconducting pairing strength near a nonmagnetic nematic quantum critical point
• Quasiparticle Nodal Plane in the Fulde-Ferrell-Larkin-Ovchinnikov State of FeSe
• The drastic effect of the impurity scattering on the electronic and superconducting properties of Cu-doped FeSe
• Near zero-energy Caroli-de Gennes-Matricon vortex states in the presence of impurities
• Spontaneous time-reversal symmetry breaking by disorder in superconductors
• Boundary effects in two-band superconductors
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• FeSe and the missing electron pocket problem
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• The phonon mechanism explanation of the superconductivity dichotomy between FeSe and FeS monolayers on STO and other substrates
• Exploring multichannel superconductivity in ThFeAsN
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• Spin fluctuations in the ultranodal superconducting state of Fe(Se,S)
• Odd-Parity Magnetism in Fe-Based Superconductors
• Representation-protected topology of spin-singlet $s$-wave superconductors
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• Studies of superconductivity of Fe chalcogenides in films grown by PLD technique
• Sublattice Dichotomy in Monolayer FeSe Superconductor
• Effects of Chemical Pressure on Superconductivity in Electrochemically Intercalated (TMA)yFe2(Se1-xSx)2 (TMA = Tetramethylammonium)
• Fractional vortex array realized at twin boundary in a nematic superconductor
• Superconducting Stiffness and Coherence Length of FeSe${}_{0.5}$Te${}_{0.5}$ Measured in Zero-Applied Field
• Thermally-induced mimicry of quantum cluster excitations and implications for the magnetic transition in FePSe${}_3$
• Antiferromagnetic order and its interplay with superconductivity in CaK(Fe${}_{1-x}$Mn${}_x$)${}_4$As${}_4$
• Dynamical Coulomb Blockade as a Signature of the Sign-Reversing Cooper Pairing Potential
• Eight-fold classification of superconducting orders
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• Vortex nucleation barriers and stable fractional vortices near boundaries in multicomponent superconductors
• Evidence for valence-bond pairing in a one-dimensional two-orbital system
• Feedback of non-local $d_{xy}$ nematicity on the magnetic anisotropy in FeSe
• Symmetry-breaking-induced topology in FeSe