Controlled electronic phases of transition metal oxides

在强关联电子系统中，各种电子相如超导电性和铁磁性相互竞争。本研究的目的是了解这种竞争的电子相位在相关电子系统中使用的数值技术。磁性半导体通过传导电子与磁性离子的耦合而显示出一些独特的性质。由于这种耦合，人们需要同时考虑半导体的电子状态和电子相关诱导磁性。在本研究中，我们结合联合收割机半导体电子态的密度泛函理论和量子Monte Carlo方法来考虑磁性离子的关联效应。此外，用动力学平均场理论阐明了关联电子系统中的热电势。

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.