Controlled electronic phases of transition metal oxides

在强相关电子系统中，各种电子相如超导性和铁磁性相互竞争。本研究旨在利用数值技术了解相关电子系统中的这种竞争电子相。磁性半导体通过导电电子和磁性离子之间的耦合表现出一些独特的性质。由于这种耦合，需要同时考虑半导体的电子态和引起磁性的电子相关。在本研究中，我们结合半导体电子态的密度泛函理论和量子蒙特卡罗方法来考虑磁性离子的相关效应。此外，用动力学平均场理论阐明了相关电子系统的热电功率。

In the strongly correlated electron systems, various electronic phases such as superconductivity and ferromagnetism are competed. This study aims to understand such competing electronic phases in the correlated electron systems by use of numerical techniques. Magnetic semiconductors show some unique properties by a coupling between conduction electrons and magnetic ions. Due to this coupling, one needs to consider simultaneously the electronic states of semiconductors and the electrons correlation inducing the magnetism. In this study, we combine the density functional theory for the electronic states of semiconductors and the quantum Monte Carlo method to include the correlation effects of magnetic ions. Furthermore, the thermoelectric power in the correlated electron systems is clarified by the dynamical mean-field theory.