随着对纳电子器件的研究深入，基于量子效应的信息存储和读写将成为下一代信息处理的理想方式。现代制备技术的提高使得多种氧化物及金属可匹配外延生长，高质量的外延铁电薄膜在几个原子晶胞的厚度上依然保持有较大的铁电极化能力,为利用多铁异质结构进行多场调控电子输运行为提供了可能。这类结合了功能材料物性与量子效应的异质结蕴含着丰富的物理现象，有望广泛应用于微纳功能器件、信息存储等领域。本项目基于对铁电材料临界尺寸、物理性能及多铁异质结构中力-电-磁耦合机理及可调性深入研究的基础之上，开展对纳尺度多铁隧穿结中的电子输运现象及其多场可控性研究。通过建立极化、压电、温度及外场相关的隧穿电流模型，研究极化反转、压电效应、界面效应等对电子隧穿电流的影响规律，重点研究纳尺度铁电层的非线性压电性能及其磁场可控性，提出实现高隧穿电阻比的设计因素，并通过实验进行验证，进而揭示获得显著隧穿电阻的可控性因素及相应条件。

With the development of nano-technology, memories based on the quantum phenomena have gained great interest. Nowadays，varies metal oxides and metals can be epitaxially grown with perfect interface, which paves a way of using mutual-fields to control the electron quantum effect. Such functional ultrathin heterostructures exist rich physics, which may have potential applications in nano-functional devices and memories. In this project, we will continue our work on the nano-scale properties of multiferroics to a further aim of studying the electron tunneling effect in multiferroics and its multi-field control ability. By considering the polarization switch, piezoelectric effect, external fields, we will firstly construct a formula of tunneling current with respect to temperature, and then devote ourselves to the tunability of ferroelectric properties by mutual external fields and the resistance change with application of external fields. Experimental work will be done along the theoretical research to enrich the theory. At last, we will discuss and conclude the factors and methods which can lead to large resistance changes.