Imaging the evolution of metallic states in a spin-orbit interaction driven correlated iridate

Abstract

The Ruddlesden-Popper (RP) series of iridates (Srn+1IrnO3n+1) have been the subject of much recent attention due to the anticipation of emergent physics arising from the cooperative action of spin-orbit (SO) driven band splitting and Coulomb interactions[1-3]. However an ongoing debate over the role of correlations in the formation of the charge gap and a lack of understanding of the effects of doping on the low energy electronic structure have hindered experimental progress in realizing many of the predicted states[4-8] including possible high-Tc superconductivity[7,9]. Using scanning tunneling spectroscopy we map out the spatially resolved density of states in the n=2 RP member, Sr3Ir2O7 (Ir327). We show that the Ir327 parent compound, argued to exist only as a weakly correlated band insulator in fact possesses a substantial ~130meV charge excitation gap driven by an interplay between structure, SO coupling and correlations. A critical component in distinguishing the intrinsic electronic character within the inhomogeneous textured electronic structure is our identification of the signature of missing apical oxygen defects, which play a critical role in many of the layered oxides. Our measurements combined with insights from calculations reveal how apical oxygen vacancies transfer spectral weight from higher energies to the gap energies thereby revealing a path toward obtaining metallic electronic states from the parent-insulating states in the iridates.

References in corpus (12)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Bandwidth-Controlled Insulator-Metal Transition and Correlated Metallic State in 5$d$ Transition Metal Oxides Sr${}_{n+1}$Ir${}_n$O${}_{3n+1}$ ($n$=1, 2, and $\infty$)
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Quantum spin Hall effect in a transition metal oxide Na2IrO3
• Visualizing the emergence of the pseudogap state and the evolution to superconductivity in a lightly hole-doped Mott insulator
• Electron correlation and Fermi surface topology of Na${}_x$CoO${}_2$
• Dimensionality controlled Mott transition and correlation effects in single- and bi-layer perovskite iridates
• Weak antiferromagnetism of J_eff=1/2 band in bilayer iridate Sr3Ir2O7
• Spin ordering and electronic texture in the bilayer iridate Sr${}_3$Ir${}_2$O${}_7$
• Local Tunneling Spectroscopy across a Metamagnetic Critical Point in the Bi-layer Ruthenate Sr3Ru2O7
• Observation of a Slater-type metal-to-insulator transition in Sr${}_2$IrO${}_4$ from time-resolved photo-carrier dynamics

Cited by in corpus (52)

• Universality of pseudogap and emergent order in lightly doped Mott insulators
• The influence of electron-doping on the ground state of (Sr{1-x}La{x})2IrO4
• Slater to Mott crossover in the metal to insulator transition of Nd2Ir2O7
• Direct observation of the Dirac nodes lifting in semimetallic perovskite SrIrO3 thin films
• Anisotropic Magnetic Couplings and Structure-Driven Canted to Collinear Transitions in Spin-orbit Coupled Sr2IrO4
• Interplay of electron-electron and electron-phonon interactions in the low temperature phase of 1T-TaS2
• Local density of states study of a spin-orbit-coupling induced Mott insulator Sr${}_2$IrO${}_4$
• Transfer of spectral weight across the gap of Sr2IrO4 induced by La doping
• Evidence for a spinon Kondo effect in cobalt atoms on single-layer 1T-TaSe${}_2$
• A charge density wave-like instability in a doped spin-orbit-assisted weak Mott insulator
• Spectroscopic evidence for negative electronic compressibility in a quasi-three-dimensional spin-orbit correlated metal
• Evidence of quantum dimer excitations in Sr${}_3$Ir${}_2$O${}_7$
• Relativistic $GW$+BSE study of the optical properties of Ruddlesden-Popper iridates
• Carrier localization and electronic phase separation in a doped spin-orbit driven Mott phase in Sr3(Ir1-xRux)2O7
• Persistent non-metallic behavior in Sr2IrO4 and Sr3Ir2O7 at high pressures
• First-order melting of a weak spin-orbit Mott insulator into a correlated metal
• Pressure-Induced Confined Metal from the Mott Insulator Sr3Ir2O7
• A weakly correlated Fermi liquid state with a small Fermi surface in lightly doped Sr${}_3$Ir${}_2$O${}_7$
• Possible Half Metallic Antiferromagnetism in a Double Perovskite Material with Strong Spin-Orbit Couplings
• Time-resolved x-ray microscopy for materials science
• Phonon-assisted optical excitation in the narrow bandgap Mott insulator Sr3Ir2O7
• Strong Pseudospin-Lattice Coupling in Sr3Ir2O7: Coherent Phonon Anomaly and Negative Thermal Expansion
• Dispersive Magnetic and Electronic Excitations in Iridate Perovskites Probed with Oxygen $K$-Edge Resonant Inelastic X-ray Scattering
• Doping Evolution of Magnetic Order and Magnetic Excitations in (Sr${}_{1-x}$La${}_x$)${}_3$Ir${}_2$O${}_7$
• Poor electronic screening in lightly doped Mott insulators observed with scanning tunneling microscopy
• Disorder induced power-law gaps in an insulator-metal Mott transition
• Direct visualization of ambipolar Mott transition in cuprate CuO2 planes
• Antiferromagnetic Slater Insulator Phase of Na2IrO3
• Pressure dependence of the structure and electronic properties of Sr3Ir2O7
• Charge partitioning and anomalous hole doping in Rh-doped Sr2IrO4
• Antiferromagnetic Excitonic Insulator State in Sr3Ir2O7
• Fermi Arcs vs. Fermi Pockets in Electron-doped Perovskite Iridates
• High chemical activity of a perovskite surface: reaction of CO with Sr${}_3$Ru${}_2$O${}_7$
• Magnetic properties of bilayer Sr${}_3$Ir${}_2$O${}_7$: role of epitaxial strain and oxygen vacancies
• High-pressure insulator-to-metal transition in Sr${}_3$Ir${}_2$O${}_7$ studied by x-ray absorption spectroscopy
• Spin correlated electronic state on the surface of a spin-orbit Mott system (Layered Iridates)
• Half metallic ferromagnetism in tri-layered perovskites Sr${}_4$T${}_3$O${}_{10}$ (T=Co, Rh)
• Imaging antiferromagnetic domain fluctuations and the effect of atomic-scale disorder in a doped spin-orbit Mott insulator
• Point defects at cleaved Sr${}_{n+1}$Ru${}_n$O${}_{3n+1}$(001) surfaces
• Time resolved photoemission of Sr${}_2$IrO${}_4$
• Symmetry-resolved two-magnon excitations in a strong spin-orbit-coupled bilayer antiferromagnet
• (Anti-)Altermagnetism from Orbital Ordering in the Ruddlesden-Popper Chromates Sr${}_{n+1}$Cr${}_n$O${}_{3n+1}$
• Percolative Mott insulator-metal transition in doped Sr${}_2$IrO${}_4$
• Exciton condensation in bilayer spin-orbit insulator
• Metal-Insulator Transitions and non-Fermi Liquid Behaviors in 5d Perovskite Iridates
• Doping driven structural distortion in the bilayer iridate (Sr${}_{1-x}$La${}_x$)${}_3$Ir${}_2$O${}_7$
• Electronic inhomogeneity and band structure on superstructural CuO2 planes of infinite-layer Sr0.94La0.06CuO2+y films
• Overdamped antiferromagnetic strange metal state in Sr${}_3$IrRuO${}_7$
• Coherent and incoherent bands in La and Rh doped Sr3Ir2O7
• Observation of linearly dispersive edge modes in a magnetic Weyl semimetal Co3Sn2S2
• Critical fluctuations in the spin-orbit Mott insulator Sr${}_3$Ir${}_2$O${}_7$
• Evolution of the spectral lineshape at the magnetic transition in Sr2IrO4 and Sr3Ir2O7