Tunable Quasi-Two-Dimensional Electron Gases in Oxide Heterostructures

• Published in: Science (American Association for the Advancement of Science) Vol. 313; no. 5795; pp. 1942 - 1945
• Main Authors: Thiel, S, Hammerl, G, Schmehl, A, Schneider, C.W, Mannhart, J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 29.09.2006; The American Association for the Advancement of Science
• Subjects: Charge carriers; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity; Density; Devices; Doping; Electric fields; Electric potential; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electrons; Epitaxial growth; Exact sciences and technology; Gases; Gates; Heterostructures; Magnetic fields; Oxides; Oxygen; Particle physics; Phase transformations; Physics; Thin films and multilayers; Voltage; Lanthanum Titanates; Electrical conductivity; Quantum phase transition; Metal-insulator transition; Modulation; Doping; Strontium titanates; Transport processes; Two-dimensional electron gas; Heterostructures
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1131091

We report on a large electric-field response of quasi-two-dimensional electron gases generated at interfaces in epitaxial heterostructures grown from insulating oxides. These device structures are characterized by doping layers that are spatially separated from high-mobility quasi-two-dimensional electron gases and therefore present an oxide analog to semiconducting high-electron mobility transistors. By applying a gate voltage, the conductivity of the electron gases can be modulated through a quantum phase transition from an insulating to a metallic state.