Comprehensive Electrical Control of Metamagnetic Transition of a Quasi‐2D Antiferromagnet by In Situ Anisotropic Strain
Comprehensive Electrical Control of Metamagnetic Transition of a Quasi‐2D Antiferromagnet by In Situ Anisotropic Strain
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DOI：
10.1002/adma.202002451
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发表时间：
2020-07
影响因子：
29.4
通讯作者：
Han Zhang;L. Hao;Junyi Yang;J. Mutch;Zhaoyu Liu;Qing Huang;K. Noordhoek;A. May;J. Chu;Jong-Woo Kim;P. Ryan;Haidong Zhou;Jian Liu
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文献类型：
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作者：
Han Zhang;L. Hao;Junyi Yang;J. Mutch;Zhaoyu Liu;Qing Huang;K. Noordhoek;A. May;J. Chu;Jong-Woo Kim;P. Ryan;Haidong Zhou;Jian Liu
对自旋结构进行有效的非磁性控制是功能量子材料研究的前沿。这项研究表明，只要施加0.05%的各向异性应变，自旋轨道耦合Mott绝缘体Sr2IrO4的变磁相变场就可以被原位调制近300%。共振X射线散射和输运的同时测量表明，这种剧烈的响应源于自旋触发器和自旋翻转极限之间的完全应变调谐，并且总是伴随着大的弹性电导和磁电导。这实现了电子可控和电子可检测的变磁开关，尽管处于反铁磁绝缘状态。得到的应变-磁场相图表明，应变通过伪自旋-晶格耦合引入了C4对称破缺各向异性，直接证明了自旋-轨道耦合复合氧化物的伪Jahn-Teller效应。所提取的耦合强度比超交换作用弱得多，但对自发对称性破缺至关重要，从而提供了非常有效的应变控制。
Effective nonmagnetic control of the spin structure is at the forefront of the study for functional quantum materials. This study demonstrates that, by applying an anisotropic strain up to only 0.05%, the metamagnetic transition field of spin–orbit‐coupled Mott insulator Sr2IrO4 can be in situ modulated by almost 300%. Simultaneous measurements of resonant X‐ray scattering and transport reveal that this drastic response originates from the complete strain‐tuning of the transition between the spin‐flop and spin‐flip limits, and is always accompanied by large elastoconductance and magnetoconductance. This enables electrically controllable and electronically detectable metamagnetic switching, despite the antiferromagnetic insulating state. The obtained strain‐magnetic field phase diagram reveals that C4‐symmetry‐breaking anisotropy is introduced by strain via pseudospin‐lattice coupling, directly demonstrating the pseudo‐Jahn–Teller effect of spin–orbit‐coupled complex oxides. The extracted coupling strength is much weaker than the superexchange interactions, yet crucial for the spontaneous symmetry‐breaking, affording the remarkably efficient strain‐control.