Metallic interfaces in a CaTiO${}_3$/LaTiO${}_3$ heterostructure

Abstract

Almost all oxide two-dimensional electron gases are formed in SrTiO${}_3$-based heterostructures and the study of non-SrTiO${}_3$ systems is extremely rare. Here, we report the realization of a two-dimensional electron gas in a CaTiO${}_3$-based heterostructure, CaTiO${}_3$/LaTiO${}_3$, grown epitaxially layer-by-layer on a NdGaO${}_3$ (110) substrate via pulsed laser deposition. The high quality of the crystal and electronic structures are characterized by in-situ reflection high-energy electron diffraction, X-ray diffraction, and X-ray photoemission spectroscopy. Measurement of electrical transport validates the formation of a two-dimensional electron gas in the CaTiO${}_3$/LaTiO${}_3$ superlattice. It is revealed the room-temperature carrier mobility in CaTiO${}_3$/LaTiO${}_3$ is nearly 3 times higher than in CaTiO${}_3$/YTiO${}_3$, demonstrating the effect of TiO${}_6$ octahedral tilts and rotations on carrier mobility of two-dimensional electron gases. Due to doped CaTiO${}_3$ being an A-site polar metal, our results provide a new route to design novel A-site two-dimensional polar metals.

References in corpus (15)

• 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
• Coexistence of superconductivity and ferromagnetism in two dimensions
• A high-mobility two-dimensional electron gas at the heteroepitaxial spinel/perovskite complex oxide interface of γ-Al2O3/SrTiO3
• Electrostatic carrier doping of GdTiO3/SrTiO3 interfaces
• Polar Discontinuity Doping of the LaVO_3/SrTiO_3 Interface
• `Ferroelectric' Metals Reexamined: Fundamental Mechanisms and Design Considerations for New Materials
• Conducting interfaces between band insulating oxides: the LaGaO3/SrTiO3
• Artificial two-dimensional polar metal at room temperature
• Tailoring Materials for Mottronics: Excess Oxygen Doping of a Prototypical Mott Insulator
• Anomalous orbital structure in a spinel-perovskite interface $\gamma$-Al${}_2$O${}_3$/SrTiO${}_3$
• Magnetic interactions at the nanoscale in trilayer titanates LaTiO${}_3$/SrTiO${}_3$/YTiO${}_3$
• Observation of a two-dimensional electron gas at CaTiO${}_3$ film surfaces
• Evolution of ferromagnetism in two-dimensional electron gas of LaTiO3/SrTiO3
• Metallic interface in non-SrTiO3 based titanate superlattice