Electronic Evidence of an Insulator-Superconductor Transition in Single-Layer FeSe/SrTiO3 Films

Abstract

In high temperature cuprate superconductors, it is now generally agreed that the parent compound is a Mott insulator and superconductivity is realized by doping the antiferromagnetic Mott insulator. In the iron-based superconductors, however, the parent compound is mostly antiferromagnetic metal, raising a debate on whether an appropriate starting point should go with an itinerant picture or a localized picture. It has been proposed theoretically that the parent compound of the iron-based superconductors may be on the verge of a Mott insulator, but so far no clear experimental evidence of doping-induced Mott transition has been available. Here we report an electronic evidence of an insulator-superconductor transition observed in the single-layer FeSe films grown on the SrTiO3 substrate. By taking angle-resolved photoemission measurements on the electronic structure and energy gap, we have identified a clear evolution of an insulator to a superconductor with the increasing doping. This observation represents the first example of an insulator-superconductor transition via doping observed in the iron-based superconductors. It indicates that the parent compound of the iron-based superconductors is in proximity of a Mott insulator and strong electron correlation should be considered in describing the iron-based superconductors.

15 pages, 4 figures

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• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• Direct observation of high temperature superconductivity in one-unit-cell FeSe films
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Cited by in corpus (40)

• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Electric-field-induced superconductivity in electrochemically-etched ultrathin FeSe films on SrTiO3 and MgO
• Common Electronic Origin of Superconductivity in (Li,Fe)OHFeSe Bulk Superconductor and Single-Layer FeSe/SrTiO3 Films
• Anomalous correlation effects and unique phase diagram of electron doped FeSe revealed by angle resolved photoemission spectroscopy
• Antiferroquadrupolar and Ising-Nematic Orders of a Frustrated Bilinear-Biquadratic Heisenberg Model and Implications for the Magnetism of FeSe
• Electronic Structure and Superconductivity of FeSe-Related Superconductors
• Ultrafast Dynamics Evidence of High Temperature Superconductivity in Single Unit Cell FeSe on SrTiO3
• The Role of SrTiO3 Phonon Penetrating into thin FeSe Films in the Enhancement of Superconductivity
• Antiferromagnetic ground state with pair-checkboard order in FeSe
• High-temperature superconductivity in one-unit-cell FeSe films
• Dichotomy of Electronic Structure and Superconductivity between Single-Layer and Double-Layer FeSe/SrTiO3 Films
• Incoherent Cooper pairing and pseudogap behavior in single-layer FeSe/SrTiO${}_3$
• How correlated is the FeSe/SrTiO${}_3$ system ?
• Oxygen Vacancy Induced Flat Phonon Mode at FeSe /SrTiO3 interface
• Thickness dependence of superconductivity and superconductor-insulator transition in ultrathin FeSe films on SrTiO3(001) substrate
• 20 K superconductivity in heavily electron doped surface layer of FeSe bulk crystal
• Extreme anisotropy and anomalous transport properties of heavily electron doped Lix(NH3)yFe2Se2 single crystals
• Odd and even modes of neutron spin resonance in the bilayer iron-based superconductor CaKFe${}_4$As${}_4$
• On peculiarities of superconductivity in the single-layer FeSe/SrTiO3 interfa
• Lattice Dynamics of Ultrathin FeSe Films on SrTiO3
• Identification of prototypical Brinkman-Rice Mott physics in a class of iron chalcogenides superconductors
• Heterostructural one-unit-cell FeSe/SrTiO3: from high-temperature superconductivity to topological states
• First-principles study of magnetic frustration in FeSe epitaxial films on SrTiO${}_3$
• Interfacial Electron-Phonon Coupling Constants Extracted from Intrinsic Replica Bands in Monolayer FeSe/SrTiO${}_3$
• Spin Fluctuation Induced Linear Magnetoresistance in Ultrathin Superconducting FeSe Films
• Band structure and charge doping effects of potassium-adsorbed FeSe/SrTiO3 system
• Superconducting transition of FeSe/SrTiO3 induced by adsorption of semiconducting organic molecules
• Identification of a Large Amount of Excess Fe in Superconducting Single-Layer FeSe/SrTiO3 Films
• Inhomogeneous superconductivity in LuxZr1-xB12 dodecaborides with dynamic charge stripes
• First-principles study of FeSe epitaxial films on SrTiO3
• Role of electric fields on enhanced electron correlation in surface-doped FeSe
• Insulating Parent Phase and Distinct Doping Evolution to Superconductivity in Single-Layer FeSe/SrTiO3 Films
• Isotropic Cooper Pairs with Emergent Sign Changes in Single-Layer Iron Superconductor
• Molecular Beam Epitaxy Growth of Tetragonal FeS Film on SrTiO3(001) Substrate
• Strong surface termination dependence of the electronic structure of polar superconductor LaFeAsO revealed by nano-ARPES
• Collective Mode at Lifshitz Transition in Iron-Pnictide Superconductors
• Lateral quantum confinement effect on monolayer high-Tc superconductors
• Capping layer influence and isotropic in-plane upper critical field of the superconductivity at the FeSe/SrTiO3 interface
• Particle-Hole Transformation in Strongly-Doped Iron-Based Superconductors
• Spectroscopic evidence of disorder-induced quantum phase transitions in monolayer Fe(Te,Se) superconductor