论文标题
方形晶格的伪静电耦合和电力控制iration sr2iro4
Pseudospin-lattice coupling and electric control of the square-lattice iridate Sr2IrO4
论文作者
论文摘要
$ \ rm sr_2iro_4 $是一种原型的旋转摩托耦合莫特绝缘子，并且由于广泛的预测新颖状态而被广泛研究。到目前为止，这些状态的实验表征有限，从而使物理特性对晶格，特别是IR-O-OIR键角的特性非常敏感。在这里，我们报告了通过单晶中子衍射测得的IRO $ _6 $ octahedra的新观察到的微观旋转。这种尖锐的晶格异常为理解异常的低温物理学和直接确认IR-O-OIR键在确定基态所起的关键作用的直接确认提供了关键。确实，正如本研究中还证明的那样，施加电流很容易通过拉直IR-O-IR键角削弱抗磁磁性，这强调了局部结构的略有变化也会不成比例地影响自旋耦合系统中的物理特性。
$\rm Sr_2IrO_4$ is an archetypal spin-orbit-coupled Mott insulator and has been extensively studied in part because of a wide range of predicted novel states. Limited experimental characterization of these states thus far brings to light the extraordinary susceptibility of the physical properties to the lattice, particularly, the Ir-O-Ir bond angle. Here, we report a newly observed microscopic rotation of the IrO$_6$ octahedra below 50~K measured by single crystal neutron diffraction. This sharp lattice anomaly provides keys to understanding the anomalous low-temperature physics and a direct confirmation of a crucial role that the Ir-O-Ir bond angle plays in determining the ground state. Indeed, as also demonstrated in this study, applied electric current readily weakens the antiferromagnetic order via the straightening of the Ir-O-Ir bond angle, highlighting that even slight change in the local structure can disproportionately affect the physical properties in the spin-orbit-coupled system.
