近年来，通过氧八面体旋转对界面量子态磁性交换相互作用或非寻常铁电相变的调控研究已经引发了广泛的研究兴趣，氧八面体调控有望成为一个新的具有广泛普适性的界面调控手段，然而发展氧八面体旋转对界面量子态的调控作用必须考虑应力的作用，一些理论已经预言了二者在氧化物界面之间密切的耦合关系及其对界面量子态的强有力调控作用，但迄今为之还没有从实验上得到证明。因而在本项目中，我们拟通过激光分子束外延制备对应力和氧八面体旋转均十分敏感的LaCoO3薄膜和超晶格，结合结构和物性表征，深入研究二者在界面附近以及远离界面处的耦合关系，发现界面量子态受二者耦合关系调控的微观机理，并发掘一些能够通过调控界面氧八面体扭转而实现磁电耦合的界面型器件材料。在界面附近发掘应力、氧八面体旋转的耦合关系，将使我们能够更清楚地了解界面附近不寻常晶格结构发生的微观机理，对设计和实现基于新型界面量子态的量子材料和器件有非常强大指导作用。

In recent years, manipulations of the oxygen octahedral rotation to control the interfacial physical properties such as the quantum exchange interaction or the improper ferroelectric phase transition have attracted a lot of research interests. And it is very likely to become a new manipulative method that can be widely applicable to many oxide interfacial systems. Naturally, strain has to be considered as we develop this new approach to tune the interfacial state. Theories have predicted that the interfacial octahedral rotation and the lattice mismatch have an intimate correlation which can apply strong impacts to the interface quantum states. However we haven't gotten proof from the experimental side. Therefore in the proposed project, we plan to use laser molecular beam epitaxy and fabricate LaCoO3 thin films and superlattices since LaCoO3 is very sensitive to both the strain and the octahedral rotation. Together with the structural and physical property measurements, we plan to study the correlation between these two factors and the mechanism of tuning the interfacial quantum state through this correlated response. Furthermore, we plan to discover some interfacial material systems in which electromagnetic cross coupling can happen by manipulation of the octahedral rotation. This study will help us to learn the microscopic mechanism of the unusual lattice structure near the interface. And more importantly, it will provide strong guidance for us to design and realize future generation electronic devices based on novel interfacial state.