The metal–insulator transition (MIT) in correlated materials is a novel phenomenon that accompanies a large change in resistivity, often many orders of magnitude. It is important in its own right but its switching behavior in resistivity can be useful for device applications. From the material physics point of view, the starting point of the research on the MIT should be to understand the microscopic mechanism. Here, an overview of recent efforts to unravel the microscopic mechanisms for various types of MITs in correlated materials is provided. Research has focused on transition metal oxides (TMOs), but transition metal chalcogenides have also been studied. Along the way, a new class of MIT materials is discovered, the so‐called relativistic Mott insulators in 5d TMOs. Distortions in the MO₆ (M = transition metal) octahedron are found to have a large and peculiar effect on the band structure in an orbital dependent way, possibly paving a way to the orbital selective Mott transition. In the final section, the character of the materials suitable for applications is summarized, followed by a brief discussion of some of the efforts to control MITs in correlated materials, including a dynamical approach using light.

中文翻译：

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相关材料中金属-绝缘体过渡机理的光谱研究

相关材料中的金属-绝缘体转变（MIT）是一种新颖的现象，伴随着电阻率的大变化，通常是多个数量级。它本身很重要，但是它在电阻率方面的切换行为对于设备应用可能是有用的。从材料物理学的角度出发，对麻省理工学院进行研究的起点应该是理解微观机理。在这里，提供了有关相关材料中各种类型的MIT的微观机理的最新研究成果的概述。研究集中在过渡金属氧化物（TMO），但也已研究了过渡金属硫属元素化物。在此过程中，发现了新型的MIT材料，即5d TMO中的相对论Mott绝缘子。MO _6中的失真（M =过渡金属）八面体以轨道相关的方式对能带结构产生了巨大而独特的影响，可能为轨道选择性Mott过渡铺平了道路。在最后一节中，总结了适合应用的材料的特性，然后简要讨论了控制相关材料中的MIT的一些努力，包括使用光的动力学方法。