Phase separation from electron confinement at oxide interfaces

Abstract

Oxide heterostructures are of great interest both for fundamental and applicative reasons. In particular the two-dimensional electron gas at the LaAlO${}_3$/SrTiO${}_3$ or LaTiO${}_3$/SrTiO${}_3$ interfaces displays many different physical properties and functionalities. However there are clear indications that the interface electronic state is strongly inhomogeneous and therefore it is crucially relevant to investigate possible intrinsic electronic mechanisms underlying this inhomogeneity. Here the electrostatic potential confining the electron gas at the interface is calculated self-consistently, finding that the electron confinement at the interface may induce phase separation, to avoid a thermodynamically unstable state with a negative compressibility. This provides a generic robust and intrinsic mechanism for the experimentally observed inhomogeneous character of these interfaces.

8 pages and 4 figures

References in corpus (9)

• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
• Intrinsic instability of electronic interfaces with strong Rashba coupling
• Evidence for charge-vortex duality at the LaAlO${}_3$/SrTiO${}_3$ interface
• Photoresponse dynamics in amorphous-LaAlO${}_3$/SrTiO${}_3$ interfaces
• Inhomogeneous multi-carrier superconductivity at LaXO3/SrTiO3 (X=Al or Ti) oxide interfaces
• Pseudo-gap in tunneling spectra as a signature of inhomogeneous superconductivity in oxide interfaces
• Spin-orbit controlled quantum capacitance of a polar heterostructure
• Interplay between density and superconducting quantum critical fluctuations

Cited by in corpus (31)

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• Physics of SrTiO${}_3$-based heterostructures and nanostructures: a review
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• Non-linear $IV$ characteristics in two-dimensional superconductors: Berezinskii-Kosterlitz-Thouless physics vs inhomogeneity
• Electronic phase separation: recent progress in the old problem
• New insights into the electron trapping mechanism in LaAlO_3 / SrTiO3 heterostructures
• Competition between electron pairing and phase coherence in superconducting interfaces
• Effect of disorder on superconductivity and Rashba spin-orbit coupling in LaAlO3/SrTiO3 interfaces
• Electronic phase separation at LaAlO3/SrTiO3 interfaces tunable by oxygen deficiency
• Orientation-dependent electron-phonon coupling in interfacial superconductors LaAlO3/KTaO3
• Band-Order Anomaly at the γ-Al2O3/SrTiO3 Interface Drives the Electron-Mobility Boost
• Universal behavior of the bosonic metallic ground state in a two-dimensional superconductor
• Negative electronic compressibility and nanoscale inhomogeneity in ionic-liquid gated two-dimensional superconductors
• Oxygen vacancies and hydrogen doping in LaAlO3/SrTiO3 heterostructures: electronic properties and impact on surface and interface reconstruction
• Correlation between Superconductivity, Band Filling and Electron Confinement at the LaAlO${}_3$-SrTiO${}_3$ Interface
• Capacitance and compressibility of heterostructures with strong electronic correlations
• Theoretical models of Rashba spin splitting in asymmetric SrTiO3-based heterostructures
• Interplay between singlet and triplet pairings in multi-band two-dimensional oxide superconductors
• Charge-Density Waves vs. Superconductivity: Some Results and Future Perspectives
• Gate-tunable superconductivity at SrTiO3 surface realized by Al layer evaporation
• Probing the Nuclear Spin-Lattice Relaxation Time at the Nanoscale
• Density inhomogeneities and Rashba spin-orbit coupling interplay in oxide interfaces
• Electric dipole spin resonance in single and two electron quantum dot defined in two-dimensional electron gas at the SrTiO${}_3$/LaAlO${}_3$ interface
• Understanding the onset of negative electronic compressibility in one- and two-band 2D electron gases: Application to LaAlO${}_3$/SrTiO${}_3$
• First-principles design of ferromagnetic monolayer MnO${}_2$ at the complex interface
• Sign-changing non-monotonic voltage gain of HfO2/Parylene-C/SrTiO3 field-effect transistor due to percolative insulator to two-dimensional metal transition
• Three-dimensionality of mobile electrons at X-ray-irradiated LaAlO${}_3$/SrTiO${}_3$ interfaces
• Superfluid response of two-dimensional filamentary superconductors
• Origin of the dome-shaped superconducting phase diagram in ${\mathrm{SrTiO}}_3$-based interfaces
• Single-band to two-band superconductivity transition in two-dimensional oxide interfaces