Crossover from coherent to incoherent scattering in spin-orbit dominated Sr2IrO4
Crossover from coherent to incoherent scattering in spin-orbit dominated Sr2IrO4
复制标题
DOI：
10.1103/physrevb.85.195148
复制
发表时间：
2012-05-29
影响因子：
3.7
通讯作者：
Takagi, Hidenori
中科院分区：
文献类型：
--
作者：
Cetin, Mehmet Fatih;Lemmens, Peter;Takagi, Hidenori
在二维化合物Sr 2 IrO 4中，强的自旋-轨道相互作用导致了J（eff）= 1/2等自旋的形成.在拉曼散射中，观察到一个归因于双磁振子散射的连续谱。随着入射激光的较高激发能量，该信号交叉成大强度的非相干信号。这种交叉的特征能量尺度与涉及Ir-O模式的声子散射中的强度共振效应相同。这种交叉与类激子轨道激发有关，这在共振X射线散射中也很明显。非相干激发的交叉和演化与它们与自旋激发的耦合有关。这表明Sr 2 IrO 4中自旋、晶格和电荷自由度的自旋-轨道诱导纠缠。
Strong spin-orbit interaction in the two-dimensional compound Sr2IrO4 leads to the formation of J(eff) = 1/2 isospins with unprecedented dynamics. In Raman scattering a continuum attributed to two-magnon scattering is observed. With higher excitation energy of the incident laser this signal crosses over to an incoherent signal of large intensity. The characteristic energy scale of this crossover is identical to that of intensity resonance effects in phonon scattering that involves Ir-O modes. This crossover is related to excitonlike orbital excitations that are also evident in resonant x-ray scattering. The crossover and the evolution of incoherent excitations are related to their coupling to spin excitations. This signals a spin-orbit induced entanglement of spin, lattice, and charge degrees of freedom in Sr2IrO4.