有效强化多铁材料铁电序-磁序参量耦合一直是多铁性研究的热点问题，多铁材料外场响应的研究也备受关注。本项目拟采用基于密度泛函理论的第一性原理和非平衡格林函数方法探索通过构造钙钛矿锰氧化物基磁电异质结构（如超晶格），产生多铁界面电子态重构，以实现局域自旋序的铁电控制。进一步研究此异质界面二维体系在晶格应力（即外延应力）畸变下的磁电耦合效应—包括铁电极化对界面自旋序、轨道磁矩、自旋极化载流子迁移特性等方面的影响，阐明钙钛矿锰氧化物界面磁化的铁电、应力双调控原理和方法；研究外延应力和铁电极化对此二维多铁系统光响应特性的影响规律，揭示其微观机制，探索通过晶格应力、界面耦合对二维多铁系统光响应进行调制的技术途径。研究结果不仅对深刻认识电子强关联体系低维界面电子态和物理性质的主动控制具有科学意义，而且能够为此类磁电材料的多功能外场调控及自旋电子器件的研制提供理论指导。

Enhancing magnetoelectric coupling always is hot issue for multiferroic research, and response to external field of multiferroics is also of great concern. In this project, the ferroelectric control of spin ordering at interface will be explored by structuring ultrathin magnetoelectric heterostructure (e.g. short-period superlattices) to generate the reconsitution of interface electronic states in perovskite manganites, using the first principles based on density function theory as well as nonequilibrium green's function. Then, we will further investigate magnetoelectric effects as lattice strain (i.e., epitaxial strain) changes for these two-dimension multiferroic systems, especially ferroelectric modulation of spin ordering, orbital magnetization and spin-polarized carrier mobility at interface. These studies are helpful to develop the ferroelectric and strain control-mechanisms of interface magnetization in perovskite manganites. The effects of epitaxial strain and electric polarization on the optical response will be studied systematically, exploring the technological approaches for modulating optical response via lattice stress and interface coupling in the two-dimension multiferroic systems with strong magnetoelectric coupling. This research not only will be of scientific significance for the active controls of low-dimension interface electron states and physical properties of strongly-correlated electron systems, but also can provide theoretical guidance for development of the multifunctional field control and spintronics devices in magnetoelectric materials.