阻变存储器中磁性原子点接触的可控构建及输运特性研究

磁性原子点接触由于量子尺寸效应而展现出弹道磁电阻、量子自旋阀、量子各向异性磁电阻等诸多新奇物理效应，在未来高密度磁存储、高灵敏磁传感等领域有广阔应用前景。然而，以机械裂结法和电化学沉积为代表的传统构建方法，不仅工艺复杂、可控性差，而且与半导体工艺不兼容，严重阻碍了磁性原子点接触的研究与实用化进程。针对这一问题，本项目提出，可在包含磁性金属电极的阻变存储器中，利用电场和磁场的协同作用来构建磁性原子点接触。相比于传统构建方法，该方法具有简单易行、可控性强、半导体工艺兼容等诸多优势，并且还有望利用磁性原子点接触与阻变介质的相互作用而获得磁电耦合、交换偏置等更多新奇物理效应。本项目拟澄清电场、磁场协同作用下阻变介质中磁性金属离子的输运过程，掌握在阻变存储器中可控构建磁性原子点接触的电场、磁场协同加载方式，阐明磁性原子点接触的磁电输运特性规律和机理，为新型高性能信息器件研发提供理论依据和技术储备。

Due to the quantum size effect, magnetic atomic point contacts (APCs) can exhibit many novel physical effects, including ballistic magnetoresistance, quantum spin-valve, quantum anisotropic magnetoresistance, etc. As such, magnetic APCs are highly promising in future high-density magnetic storage, high-sensitivity magnetic detection, and so on. However, the conventional construction methods of magnetic APCs, such as mechanical break junction and electrodeposition, are complex in process, poor in controllability and also incompatible with the standard CMOS process, hindering seriously the research and application progresses of magnetic APCs. To solve this issue, we propose the construction of magnetic APCs in resistive random access memory (RRAM) through the synergistic effect of electric and magnetic fields. Compared with the conventional ones, our method is certainly more practicable and controllable. Meanwhile, it has full compatibility with the standard CMOS process and may even bring about additional physical effects, such as magnetoelectric coupling and exchange bias, through the interaction between magnetic APCs and resistive switching media. In this project, we will first reveal the transport process of magnetic cations, driven by the synergistic effect of electric and magnetic fields, in resistive switching media. Then, the co-loading method of electric and magnetic fields to controllably construct magnetic APCs in RRAM is expected to be developed. Finally, based on controllably constructed magnetic APCs, their transport properties and related mechanisms will be clarified. The obtained results would provide theories and techniques for developing novel and high-performance information devices in future.