Revealing Controllable Anisotropic Magnetoresistance in Spin–Orbit Coupled Antiferromagnet Sr2IrO4
Revealing Controllable Anisotropic Magnetoresistance in Spin–Orbit Coupled Antiferromagnet Sr2IrO4
复制标题
揭示自旋轨道耦合反铁磁体 Sr2IrO4 中的可控各向异性磁阻
DOI：
10.1002/adfm.201706589
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发表时间：
2018
影响因子：
19
通讯作者：
Liu J.-M.
中科院分区：
文献类型：
--
作者：
Lu C.;Gao B.;Wang H.;Wang W.;Yuan S.;Dong S.;Liu J.-M.
反铁磁自旋电子学积极地引入了磁存储器的新原理，其中最基本的自旋相关现象，即，各向异性磁阻效应由反铁磁体而不是铁磁体控制。反铁磁各向异性磁电阻效应的一般情况主要源于与自旋轨道耦合有关的磁晶各向异性。本文研究了磁场驱动下具有强自旋-轨道耦合Jeff = 1/2 Mott态的反铁磁Sr_2IrO_4/SrTiO_3（001）裸薄膜的四重各向异性磁电阻的轮廓旋转。同时，一个有趣的最小磁阻出现。通过第一性原理计算，发现这些现象是由于Ir等自旋的旋转引起的带隙工程，这与传统的沿磁易轴沿着施加磁场时通常获得相对更导电的状态的情况不同.这些发现证明了一种新的有效途径，即，通过新颖的Jeff = 1/2态，实现了反铁磁材料中可控的各向异性磁电阻。
Antiferromagnetic spintronics actively introduces new principles of magnetic memory, in which the most fundamental spin‐dependent phenomena, i.e., anisotropic magnetoresistance effects, are governed by an antiferromagnet instead of a ferromagnet. A general scenario of the antiferromagnetic anisotropic magnetoresistance effects mainly stems from the magnetocrystalline anisotropy related to spin–orbit coupling. Here magnetic field driven contour rotation of the fourfold anisotropic magnetoresistance in bare antiferromagnetic Sr2IrO4/SrTiO3(001) thin films hosting a strong spin–orbit coupling inducedJeff= 1/2 Mott state is demonstrated. Concurrently, an intriguing minimal in the magnetoresistance emerges. Through first principles calculations, the bandgap engineering due to rotation of the Ir isospins is revealed to be responsible for these emergent phenomena, different from the traditional scenario where relatively more conductive state is obtained usually when magnetic field is applied along the magnetic easy axis. These findings demonstrate a new efficient route, i.e., via the novelJeff= 1/2 state, to realize controllable anisotropic magnetoresistance in antiferromagnetic materials.