Disorder induced power-law gaps in an insulator-metal Mott transition

Abstract

A correlated material in the vicinity of an insulator-metal transition (IMT) exhibits rich phenomenology and variety of interesting phases. A common avenue to induce IMTs in Mott insulators is doping, which inevitably leads to disorder. While disorder is well known to create electronic inhomogeneity, recent theoretical studies have indicated that it may play an unexpected and much more profound role in controlling the properties of Mott systems. Theory predicts that disorder might play a role in driving a Mott insulator across an IMT, with the emergent metallic state hosting a power law suppression of the density of states (with exponent close to 1; V-shaped gap) centered at the Fermi energy. Such V-shaped gaps have been observed in Mott systems but their origins are as yet unknown. To investigate this, we use scanning tunneling microscopy and spectroscopy to study isovalent Ru substitutions in Sr${}_3$(Ir${}_{1-x}$Ru${}_x$)${}_2$O${}_7$ which drives the system into an antiferromagnetic, metallic state. Our experiments reveal that many core features of the IMT such as power law density of states, pinning of the Fermi energy with increasing disorder, and persistence of antiferromagnetism can be understood as universal features of a disordered Mott system near an IMT and suggest that V-shaped gaps may be an inevitable consequence of disorder in doped Mott insulators.

arXiv comment13 pages, 4 figures; A new version can be find in PNAS

References in corpus (40)

• Complexity in Strongly Correlated Electronic Systems
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• A `checkerboard' electronic crystal state in lightly hole-doped Ca_{2-x}Na_{x}CuO_{2}Cl_{2}
• An Intrinsic Bond-Centered Electronic Glass with Unidirectional Domains in Underdoped Cuprates
• 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 $\infty$)
• Defects in correlated metals and superconductors
• Distinct Fermi-Momentum Dependent Energy Gaps in Deeply Underdoped Bi2212
• Fermi Arcs in a Doped Pseudospin-1/2 Heisenberg Antiferromagnet
• Observation of a $d$-wave gap in electron-doped Sr${}_2$IrO${}_4$
• Nodal quasiparticle in pseudogapped colossal magnetoresistive manganites
• Visualizing Critical Correlations near the Metal-Insulator Transition in Ga1-xMnxAs
• Mott--Hubbard transition vs. Anderson localization of correlated, disordered electrons
• Mean field theory of the Mott-Anderson transition
• Where Are the Extra d Electrons in Transition-Metal Substituted Fe Pnictides?
• Signature of high temperature superconductivity in electron doped Sr2IrO4
• Visualizing the emergence of the pseudogap state and the evolution to superconductivity in a lightly hole-doped Mott insulator
• Visualizing the evolution from the Mott insulator to a charge ordered insulator in lightly doped cuprates
• Universality of pseudogap and emergent order in lightly doped Mott insulators
• Coulomb Gap: How a Metal Film Becomes an Insulator
• Orbital-driven Mottness collapse in 1T-TaS2-xSex transition metal dichalcogenide
• Imaging the evolution of metallic states in a spin-orbit interaction driven correlated iridate
• Dilute Magnetism and Spin-Orbital Percolation Effects in Rh-doped Sr2IrO4
• Critical behavior at Mott-Anderson transition: a TMT-DMFT perspective
• Inhomogeneous metallic phase upon disordering a two dimensional Mott insulator
• Emergent Novel Metallic State in a Disordered 2D Mott Insulator
• Tuning Jeff = 1/2 Insulating State via Electron Doping and Pressure in Double-Layered Iridate Sr3Ir2O7
• Probing the role of Co substitution in the electronic structure of iron-pnictides
• Single-particle excitations under coexisting electron correlation and disorder: a numerical study of the Anderson-Hubbard model
• Soft Hubbard gaps in disordered itinerant models with short-range interaction
• Carrier localization and electronic phase separation in a doped spin-orbit driven Mott phase in Sr3(Ir1-xRux)2O7
• Disorder-Induced Stabilization of the Pseudogap in Strongly Correlated Systems
• A Mott insulator continuously connected to iron pnictide superconductors
• Local Tunneling Spectroscopy across a Metamagnetic Critical Point in the Bi-layer Ruthenate Sr3Ru2O7
• Evolution of competing magnetic order in the Jeff=1/2 insulating state of Sr2Ir1-xRuxO4
• The role of strong electronic correlations in the metal-to-insulator transition in disordered LiAl_yTi_(2-y)O_4
• Universal quantum criticality at the Mott-Anderson transition
• Evolution of Fermi surface and normal-state gap in chemically substituted cuprates Bi${}_2$Sr${}_{2-x}$Bi${}_x$CuO${}_{6+\delta }$
• Strong similarities between the local electronic structure of insulating iron pnictide and lightly doped cuprate
• Giant Spin Gap and Magnon Localization in the Disordered Heisenberg Antiferromagnet Sr2Ir1-xRuxO4
• Analysis of the Disorder-Induced Zero Bias Anomaly in the Anderson-Hubbard Model

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• Local Spectroscopies Reveal Percolative Metal in Disordered Mott Insulators
• Nonequilibrium DMFT+CPA for Correlated Disordered Systems
• Origin of the different electronic structure of Rh- and Ru-doped Sr2IrO4
• Disorder-controlled relaxation in a 3D Hubbard model quantum simulator
• Anderson localization effects on doped Hubbard model
• Conductivity of Dirac-like surface states in correlated honeycomb transition metal oxide Mott insulators
• Evolution of the spectral lineshape at the magnetic transition in Sr2IrO4 and Sr3Ir2O7
• Emergent soft-gap Anderson models at quantum criticality in a lattice Hamiltonian within dynamical mean field theory
• Spectroscopic evidence of disorder-induced quantum phase transitions in monolayer Fe(Te,Se) superconductor