Metal-Insulator Transition of the LaAlO3-SrTiO3 Interface Electron System

Abstract

We report on a metal-insulator transition in the LaAlO3-SrTiO3 interface electron system, of which the carrier density is tuned by an electric gate field. Below a critical carrier density n_c ranging from 0.5-1.5 * 10^13/cm^2, LaAlO3-SrTiO3 interfaces, forming drain-source channels in field-effect devices are non-ohmic. The differential resistance at zero channel bias diverges within a 2% variation of the carrier density. Above n_c, the conductivity of the ohmic channels has a metal-like temperature dependence, while below n_c conductivity sets in only above a threshold electric field. For a given thickness of the LaAlO3 layer, the conductivity follows a sigma_0 ~(n - n_c)/n_c characteristic. The metal-insulator transition is found to be distinct from that of the semiconductor 2D systems.

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References in corpus (5)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Metal-insulator transition in two-dimensional electron systems
• Shubnikov-de Haas oscillations in SrTiO3\LaAlO3 interface
• The Observation of Percolation-Induced 2D Metal-Insulator Transition in a Si MOSFET

Cited by in corpus (19)

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• Physics of SrTiO${}_3$-based heterostructures and nanostructures: a review
• Nanoscale Phenomena in Oxide Heterostructures
• A Gate-tunable Polarized Phase of Two-Dimensional Electrons at the LaAlO3/SrTiO3 Interface
• Giant Oscillating Thermopower at Oxide Interfaces
• New insights into the electron trapping mechanism in LaAlO_3 / SrTiO3 heterostructures
• Localization of Two-dimensional Electron Gas in LaAlO3/SrTiO3 Heterostructures
• Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface
• Gate-tunable Rashba spin-orbit coupling and spin polarization at diluted oxide interfaces
• Anomalous response to gate voltage application in mesoscopic LaAlO_3/SrTiO_3 devices
• Electric-field-induced pyroelectric order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Non-universal current flow near the metal-insulator transition in an oxide interface
• Influence of the ferroelectric quantum critical point on SrTiO${}_3$ interfaces
• Temperature-Dependent Band Structure of SrTiO${}_3$ Interfaces
• Spin-orbit controlled quantum capacitance of a polar heterostructure
• Inhomogeneous superconductivity and quasilinear magnetoresistance at amorphous LaTiO3/SrTiO3 interfaces
• Reversible and Persistent Photoconductivity at the NdGaO3/SrTiO3 Conducting Interface
• Modified transverse Ising model for the dielectric properties of SrTiO${}_3$ films and interfaces