钙钛矿氧化物异质结自旋极化输运机制研究

Mechanism of spin-polarized transport in perovskite oxide heterojunctions

摘要: 文章介绍了一个基于弱Hund耦合规则以及载流子漂移扩散机制所提出的关于钙钛矿氧化物p-n异质结构的自旋极化输运机制的物理模型.该理论不仅可以很好地解释由具有负磁阻效应的La0.9Sr0.1MnO3（LSMO）与非磁性的SrNb0.01Ti0.99O3（SNTO）所组成的异质结中所存在的正磁电阻效应，同时揭示了该体系中LSMO在界面区域的载流子与远离界面区域的载流子具有不同的自旋极化方向.这一结果将为理解钙钛矿氧化物异质结及多层膜的自旋极化输运机制开辟了一条新的途径.

Abstract: A model of spin-polarized transport in perovskite oxide p-n heterostructures is introduced based on the weak Hund coupling and semiconductor energy band theory. The positive colossal magnetoresistance (CMR) effect in the heterojunction of La0.9Sr0.1MnO3/SrNb0.01Ti0.99O3 (LSMO/SNTO), which is composed of the negative CMR material LSMO and the nonmagnetic material SNTO, can be explained by using this model. Our theory paves a novel way for the understanding of the spin-polarized transport mechanism in these oxide heterostructures.