Development of the microscopic theory on anomalous electronic states in hollandite-type transition-metal oxides

我们研究了具有Hollandite类型晶体结构的过渡金属氧化物的反常电子性质的机制。我们使用基于密度泛函理论的第一性原理电子结构计算，以及基于变分团簇近似和密度矩阵重整化群方法的模型计算。重点阐述了氧化Ru准一维电子态的起源，氧化铬中完美铁磁性和金属-绝缘体转变的机制，以及氧化钼中超原子晶体的形成机制。

We study the mechanisms of anomalous electronic properties of transition-metal oxides with hollandite-type crystal structure. We use the first-principles electronic structure calculations based on the density functional theory as well as the model calculations based on the variational cluster approximation and density-matrix renormalization group method. We in particular clarify the origin of the quasi-one-dimensional electronic state of ruthenium oxide, mechanism of the perfect ferromagnetism and metal-insulator transition in chromium oxide, and mechanism of the formation of the superatomic crystal in molybdenum oxide.