Nature of electrons from oxygen vacancies and polar catastrophe at LaAlO3/SrTiO3 interfaces

Abstract

The relative significance of quantum conductivity correction and magnetic nature of electrons in understanding the intriguing low-temperature resistivity minimum and negative magnetoresistance of the two-dimensional electron gas at LaAlO3/SrTiO3 interfaces has been a long outstanding issue since its discovery. Here we report a comparative magnetotransport study on amorphous and oxygen-annealed crystalline LaAlO3/SrTiO3 heterostructures at a relatively high-temperature range, where the orbital scattering is largely suppressed by thermal fluctuations. Despite of a predominantly negative out-of-plane magnetoresistance effect for both, the magnetotransport is isotropic for amorphous LaAlO3/SrTiO3 while strongly anisotropic and well falls into a two-dimensional quantum correction frame for annealed crystalline LaAlO3/SrTiO3. These results clearly indicate that a large portion of electrons from oxygen vacancies are localized at low temperatures, serving as magnetic centers, while the electrons from the polar field are only weakly localized due to constructive interference between time-reversed electron paths in the clean limit and no signature of magnetic nature is visible.

arXiv comment9 pages, 4 figures. Accepted in Journal of Physics: Condensed Matter

References in corpus (26)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface
• Coexistence of Magnetic Order and Two-dimensional Superconductivity at LaAlO${}_3$/SrTiO${}_3$ Interfaces
• The role of oxygen vacancies in SrTiO3 at the LaAlO3/SrTiO3 interface
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Coexistence of superconductivity and ferromagnetism in two dimensions
• Crossover between weak localization and weak antilocalization in magnetically doped topological insulator
• Metallic and insulating interfaces of amorphous SrTiO3-based oxide heterostructures
• Physics of SrTiO${}_3$-based heterostructures and nanostructures: a review
• Origin of the two-dimensional electron gas at LaAlO3/SrTiO3 interfaces: The role of oxygen vacancies and electronic reconstruction
• Anisotropic magneto-transport effects at SrTiO3\LaAlO3 interfaces
• Carrier freeze-out induced metal-insulator transition in oxygen deficient SrTiO3 films
• Oxygen vacancies at titanate interfaces: two-dimensional magnetism and orbital reconstruction
• A Gate-tunable Polarized Phase of Two-Dimensional Electrons at the LaAlO3/SrTiO3 Interface
• Antisymmetric magnetoresistance of the SrTiO3/LaAlO3 interface
• Weak-localization and spin-orbit interaction in side-gate field effect devices at the LaAlO${}_3$/SrTiO${}_3$ interface
• Growth-induced electron mobility enhancement at the LaAlO${}_3$/SrTiO${}_3$ interface
• Controlling Kondo-like Scattering at the SrTiO3-based Interfaces
• Magnetic-field induced resistivity minimum with in-plane linear magnetoresistance of the Fermi liquid in SrTiO3-x single crystals
• Tuning the two-dimensional electron liquid at oxide interfaces by buffer-layer-engineered redox reactions
• Dominant role of oxygen vacancies in electrical properties of unannealed LaAlO3/SrTiO3 interfaces
• Thermally excited multi-band conduction in LaAlO3/SrTiO3 heterostructures exhibiting magnetic scattering
• A two-dimensional electron gas based on a 5s oxide with high room-temperature mobility and strain sensitivity
• Transport and thermoelectric properties of the LaAlO${}_3$/SrTiO${}_3$ interface
• Weak localization competes with the quantum oscillations in a natural electronic superlattice: the case of Na${}_{1.5}$(PO${}_2$)${}_4$(WO${}_3$)${}_{20}$

Cited by in corpus (1)

• Pressure-Induced Metal-Insulator and Paramagnet-Altermagnet Transitions in Rutile OsO2 Single Crystals