Mott Variable Range Hopping and Weak Antilocalization Effect in Heteroepitaxial Na2IrO3 Thin Films

Abstract

Iridate thin films are a prerequisite for any application utilizing their cooperative effects resulting from the interplay of stron spin-orbit coupling and electronic correlations. Here, heteroepitaxial Na2IrO3 thin films with excellent (001) out-of-plane crystalline orientation and well defined in-plane epitaxial relationship are presented on various oxide substrates. Resistivity is dominated by a three-dimensional variable range hopping mechanism in a large temperature range between 300 K and 40 K. Optical experiments show the onset of a small optical gap of about 200 meV and a splitting of the Ir 5d-t2g manifold. Positive magnetoresistance below 3 T and 25 K shows signatures of a weak antilocalization effect. This effect can be associated with surface states in a topological insulator and hence supports proposals for a topological insulator phase present in Na2IrO3.

7 pages, 3 figures, 1 table

References in corpus (20)

• Non-Abelian Anyons and Topological Quantum Computation
• Topological Insulators with Inversion Symmetry
• 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
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Spin waves and revised crystal structure of honeycomb iridate Na2IrO3
• Spin-Liquid State in the S = 1/2 Hyperkagome Antiferromagnet Na4Ir3O8
• 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 $\infty$)
• Impurity effect on weak anti-localization in the topological insulator Bi2Te3
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Quantum spin Hall effect in a transition metal oxide Na2IrO3
• Direct evidence of a zigzag spin chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation on single crystal $\mathrm{N}{\mathrm{a}}_2\mathrm{Ir}{\mathrm{O}}_3$
• Long range magnetic ordering in Na${}_2$IrO${}_3$
• Tunable Surface Conductivity in Bi2Se3 Revealed in Diffusive Electron Transport
• Na2IrO3 as a spin-orbit-assisted antiferromagnetic insulator with a 340 meV gap
• Possible proximity of the Mott insulating Iridate Na2IrO3 to a topological phase: Phase diagram of the Heisenberg-Kitaev model in a magnetic field
• Gapless spin liquids on the three dimensional hyper-kagome lattice of Na${}_4$Ir${}_3$O${}_8$
• Topological Quantum Phase Transition in 5$d$ Transition Metal Oxide Na${}_2$IrO${}_3$
• NaIrO3 - A pentavalent post-perovskite
• IrSr_2Sm_{1.15}Ce_{0.85}Cu_{2.175}O_{10}: A Novel Reentrant Spin-Glass Material

Cited by in corpus (23)

• Spiral order in the honeycomb iridate Li2IrO3
• Rashba spin orbit coupling in the Kane-Mele-Hubbard model
• Pressure-tuned magnetic interactions in honeycomb Kitaev materials
• Temperature evolution of magnetic and transport behavior in 5\textit{d} Mott insulator Sr${}_2$IrO${}_4$: Significance of magneto-structural coupling
• Nonequilibrium low temperature phase in pyrochlore iridate Y${}_2$Ir${}_2$O${}_7$: Possibility of glass-like dynamics
• Topological Properties and Functionalities in Oxide Thin Films and Interfaces
• Interlayer Coupling Effect on a Bilayer Kitaev Model
• Electronic Structure and Magnetic Properties of Iridate Superlattice SrIrO${}_3$/SrTiO${}_3$
• Anisotropic Quantum Spin Hall Effect, Spin-Orbital Textures and Mott Transition
• Coexistence of high electrical conductivity and weak ferromagnetism in Cr doped Y${}_2$Ir${}_2$O${}_7$ pyrochlore iridate
• Electronic excitations and structure of Li2IrO3 thin films grown on ZrO${}_2$:Y (001) substrates
• Honeycomb oxide heterostructure: a new platform for Kitaev quantum spin liquid
• Suppression of Antiferromagnetic Order by Strain in Honeycomb Cobaltate: Implication for Quantum Spin Liquid
• Interface induced exchange bias effect in La${}_{0.67}$Sr${}_{0.33}$MnO${}_3$/SrIrO${}_3$ multilayer
• Nonmagnetic substitution in pyrochlore iridate Y${}_2$(Ir${}_{1-x}$Ti${}_x$)${}_2$O${}_7$: Structure, magnetism and electronic properties
• The Emerging Weak Antilocalization Effect in Semimetal Ta${}_{0.7}$Nb${}_{0.3}$Sb${}_2$ Single Crystal
• Competition between magnetic order and charge localization in Na${}_2$IrO${}_3$ thin crystal devices
• Magnetism and electrical transport in Y-doped layered iridate Sr${}_2$IrO${}_4$
• Evidence for weak antilocalization-weak localization crossover and metal-insulator transition in CaCu${}_3$Ru${}_4$O${}_{12}$ thin films
• Optical detection of bond-dependent and frustrated spin in the two-dimensional cobalt-based honeycomb antiferromagnet Cu3Co2SbO6
• Topological Characterization of Kitaev Spin Nanoribbons with Ordered Flux Configurations
• Metallic conductivity on Na-deficient structural domain walls in the spin-orbit Mott insulator Na${}_2$IrO${}_3$
• Possibility of an unconventional spin state of Ir${}^{4+}$ in Ba${}_{21}$Ir${}_9$O${}_{43}$ single crystal