Lattice-driven magnetoresistivity and metal-insulator transition in single-layered iridates
Lattice-driven magnetoresistivity and metal-insulator transition in single-layered iridates
复制标题
DOI：
10.1103/physrevb.84.100402
复制
发表时间：
2011-09-09
影响因子：
3.7
通讯作者：
Cao, G.
中科院分区：
文献类型：
--
作者：
Ge, M.;Qi, T. F.;Cao, G.
Sr 2 IrO 4表现出由自旋-轨道相互作用驱动的绝缘状态。我们报告了两个现象，即，一个大的磁阻在Sr 2 IrO 4是非常敏感的磁场的方向，但没有表现出明显的相关性与磁化强度，和一个强大的金属状态，诱导稀电子（La 3+）或空穴（K+）掺杂的Sr 2+离子在Sr 2 IrO 4。我们的结构、输运和磁性数据表明，强的自旋-轨道相互作用极大地改变了竞争能量之间的平衡，以至于（1）自旋自由度不再是主导力，（2）潜在的输运性质通过强磁弹性耦合微妙地取决于Ir-O-Ir键角，以及（3）Sr 2 IrO 4中的高绝缘状态接近于金属状态，并且该转变由晶格畸变控制，该晶格畸变可以通过磁场或化学掺杂来控制。
Sr2IrO4 exhibits an insulating state driven by spin-orbit interactions. We report two phenomena, namely, a large magnetoresistivity in Sr2IrO4 that is extremely sensitive to the orientation of magnetic field but exhibits no apparent correlation with the magnetization, and a robust metallic state that is induced by dilute electron (La3+) or hole (K+) doping for Sr2+ ions in Sr2IrO4. Our structural, transport, and magnetic data reveal that a strong spin-orbit interaction alters the balance between the competing energies so greatly that (1) the spin degree of freedom alone is no longer a dominant force, (2) the underlying transport properties delicately hinge on the Ir-O-Ir bond angle via a strong magnetoelastic coupling, and (3) a highly insulating state in Sr2IrO4 is proximate to a metallic state, and the transition is governed by lattice distortions that can be controlled via either the magnetic field or chemical doping.