Two-dimensional electron gas at oxides interfaces

Transition metal oxides have attracted much attention in recent decades for the richness of their phase diagrams that reveal a variety of electronic properties ranging from high-Tc superconductivity to colossal magnetoresistance. As these materials have comparable lattice parameters, they can be combined artificial heterostructures with atomically flat interface, which provides unique opportunities for the generation of novel emergent properties and functionalities. In this context, the discovery of a superconducting two-dimensional electron gas at the interface between two insulating oxides such as LaAlO3 and SrTiO3 has generated a considerable interest. In these heterostructures, the 2-DEG is confined in an interfacial quantum well that extends to approximately 10 nm into the SrTiO3 substrate at low temperature. The superconducting transition temperature Tc can be tuned over a wide range by means of electrostatic gating, which allows a superconducting phase diagram of this interface to be derived. The breaking of translational symmetry in the interfacial quantum well also generates a spin-orbit coupling of Rashba type, whose strength can be tuned by a gate voltage.
The PHASME team studies the properties of these electronic systems by dc and microwave low-temperature electronic transport.

Main references :

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