简介: |
Oxide heterostructures have attracted considerable attention in recent years due to the emerging novel behavior which does not exist in the corresponding bulk parent compounds. In 2004, Ohtomo and Hwang discovered the interface between two insulating perovskite oxides LaAlO3 and SrTiO3 along (001) to be metallic with high carrier mobility. Subsequent studies showed that the conducting sheet is confined to a few nanometers on the SrTiO3 side of the interface and behaves like a two dimensional electron gas (2DEG). The 2DEG continues to attract much attention with reports that it can be conducting, strong spin-orbit coupling, correlated, magnetic, and even superconducting.
In this talk, I will focus on the origin and properties of the 2DEG. I will show (i) polarityinduced-oxygen vacancies as the origin of the 2DEG, (ii) theory of spin-orbit coupling at the oxide interfaces, and (iii) some unusual and unique properties of perovskite oxide heterostructure along (110). In addition, I will also present our recent DFT + dynamical mean field theory (DMFT) results of strongly correlated oxide heterostructures such as SrVO3 and SrRuO3 ultrathin films.
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