Hard x-ray angle-resolved photoemission from a buried high-mobility electron system

Abstract

Novel two-dimensional electron systems at the interfaces and surfaces of transition-metal oxides recently have attracted much attention as they display tunable, intriguing properties that can be exploited in future electronic devices. Here we show that a high-mobility quasi-two-dimensional electron system with strong spin-orbit coupling can be induced at the surface of a KTaO${}_3$ (001) crystal by pulsed laser deposition of a disordered LaAlO${}_3$ film. The momentum-resolved electronic structure of the buried electron system is mapped out by hard x-ray angle-resolved photoelectron spectroscopy. From a comparison to calculations it is found that the band structure deviates from that of electron-doped bulk KTaO${}_3$ due to the confinement to the interface. Nevertheless, the Fermi surface appears to be clearly three-dimensional. From the $k$ broadening of the Fermi surface and core-level depth profiling we estimate the extension of the electron system to be at least 1 nm but not much larger than 2 nm, respectively.

arXiv comment13 pages, 7 figures

References in corpus (25)

• Spintronics: Fundamentals and applications
• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Electronic transport in two dimensional graphene
• Magnetic effects at the interface between nonmagnetic oxides
• Tunable Rashba spin-orbit interaction at oxide interfaces
• 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
• Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface
• Metallic and insulating interfaces of amorphous SrTiO3-based oxide heterostructures
• A high-mobility two-dimensional electron gas at the heteroepitaxial spinel/perovskite complex oxide interface of γ-Al2O3/SrTiO3
• Profiling the interface electron gas of LaAlO3/SrTiO3 heterostructures by hard X-ray photoelectron spectroscopy
• Discovery of two-dimensional anisotropic superconductivity at KTaO${}_3$ (111) interfaces
• Two-dimensional superconductivity at the surfaces of KTaO3 gated with ionic liquid
• Subband structure of a two-dimensional electron gas formed at the polar surface of the strong spin-orbit perovskite KTaO${}_3$
• Charge writing at the LaAlO3/SrTiO3 surface
• Mixed Dimensionality of Confined Conducting Electrons in the Surface Region of SrTiO${}_3$
• Intrinsic Mobility Limiting Mechanisms in Lanthanum-doped Strontium Titanate
• Spin-charge interconversion in KTaO${}_3$ two-dimensional electron gases
• Band Structure and Spin-Orbital Texture of the (111)-KTaO3 Two-Dimensional Electron Gas
• Oxygen vacancy induced electronic structure modification of KTaO${}_3$
• Growth-induced electron mobility enhancement at the LaAlO${}_3$/SrTiO${}_3$ interface
• Transport properties of KTaO${}_3$ from first-principles
• Electronic Structure of the Dilute Magnetic Semiconductor $G{a}_{1-x}M{n}_{x}P$ from Hard X-ray Photoelectron Spectroscopy and Hard X-ray Angle-Resolved Photoemission
• Bulk Electronic Structure of Lanthanum Hexaboride (LaB6) by Hard X-ray Angle-Resolved Photoelectron Spectroscopy
• Quantum interference effects of out-of-plane confinement on two-dimensional electron systems in oxides

Cited by in corpus (3)

• Orientation-dependent electron-phonon coupling in interfacial superconductors LaAlO3/KTaO3
• Evidence of linear and cubic Rashba effect in non-magnetic heterostructure
• Orientation-dependent superconductivity and electronic structure of the rare-earth metal/KTaO3 interfaces