Systematic investigation of optical and electronic features of spin-charge-photon coupled systems

通过不同专业知识的结合，我们探索了由强相关电子系统的介电和磁响应之间的强耦合引起的新的电子和光学功能。Miyano小组：我们开发了薄膜制造技术，允许与强相关系统相变相关的晶格变形。该薄膜具有持久的光致绝缘体/金属过渡、新颖的磁电阻和稳定的两相共存。由于薄膜的单畴性质，现在可以获得完全的各向异性。Tokura小组：我们已经探索了由非平凡自旋织构引起的不寻常的介电响应。在极性铁磁体中，我们发现了由环形矩引起的非平凡光学非线性克尔旋转和定向二色性等光磁电效应。在摆线磁体中发现了磁致铁电体，其极化可以在很大程度上由外加磁场改变。Kanoda组：我们探索了具有自旋-电荷和电荷-晶格耦合的分子材料的新量子相。我们在自旋液体的Mott跃迁附近发现了由于自旋受挫和电荷波动而导致的反常相和超导性，并观察了在中性离子跃迁附近晶格二聚化和电荷转移的量子临界波动。Nagaosa小组：我们研究了与Berry相相关的新量子现象。在考虑无序效应的情况下，我们建立了反常霍尔效应和自旋霍尔效应的统一全局理论，并与实验得到了很好的定量一致。我们还发展了光和激子的自旋霍尔效应理论。Gonokami小组：我们研究了电子和空穴强相关系统中的新光学现象和功能，包括Mn离子掺杂GaAs的太赫兹发射增强和与磁序相关的强中隙杂质诱导吸收。我们还开发了一种适用于非接触式霍尔测量的高灵敏度偏振法。少

By a combination of different expertises, we explored new electronic and optical functions arising from the strong coupling between the dielectric and magnetic responses of strongly correlated electron systems.Miyano group : We developed thin-film fabrication technique that allows lattice deformations associated with the phase transition of strongly correlated systems. The films display persistent photo-induced insulator/metal transition, novel magnetoresistance, and stable two-phase coexistence. The full anisotropic properties are now accessible due to the mono-domain quality of the films.Tokura group : We have explored unusual dielectric response caused by nontrivial spin textures. In a polar ferrimagnet, we have found the optical magnetoelectric effects such as nontrivial optical nonlinear Kerr rotation and directional dichroism as induced by the toroidal moments. Magnetically induced ferroelectrics is discovered, in cycloidal magnets in which the polarization can be largely modifie … More d by external magnetic field.Kanoda group : We explored new quantum phases of molecular materials with spin-charge and charge-lattice coupling. We found an anomalous phase and superconductivity due to spin frustration and charge fluctuations in the vicinity of the Mott transition of spin liquid and observed the quantum critical fluctuations of lattice dimerization and charge transfer around the neutral-ionic transition.Nagaosa group : We examined the novel quantum phenomena related to the Berry phase. Taking into account the disorder effect, we have constructed the unified and global theory of the anomalous and spin Hall effects and attained the good quantitative agreements with the experiments. We also developed the theory of spin Hall effect of light and excitons.Gonokami group : We investigated new optical phenomena and functions in systems where electrons and holes are strongly correlated, including enhanced terahertz emission from Mn ion doped GaAs and strong mid- gap impurity-induced absorption associated with magnetic order. We also developed a highly sensitive polarimetry method that is applicable to non-contact Hall measurement. Less