Signatures of non-Loudon-Fleury Raman scattering in the Kitaev magnet β−Li2IrO3
Signatures of non-Loudon-Fleury Raman scattering in the Kitaev magnet β−Li2IrO3
复制标题
Kitaev 磁体 βLi2IrO3 中非劳登-弗勒里拉曼散射的特征
DOI：
10.1103/physrevb.105.l241101
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发表时间：
2022
影响因子：
3.7
通讯作者：
Perkins, Natalia B.
中科院分区：
文献类型：
--
作者：
Yang, Yang;Wang, Yiping;Rousochatzakis, Ioannis;Ruiz, Alejandro;Analytis, James G.;Burch, Kenneth S.;Perkins, Natalia B.
利用非弹性拉曼散射研究了超蜂窝Kitaev磁体的磁激发。的光谱表现出共存的一个广泛的散射连续和两个尖锐的低能量峰在2.5和3毫电子伏，具有独特的偏振依赖性。虽然连续体暗示了从接近的量子自旋液相中出现的分数准粒子，但是尖锐的峰提供了最近提出的“非Loudon- Fleury”单磁振子散射过程的第一个实验特征[Yanget al.，Phys. Rev. B 104，144412（2021）2469-995010.1103/PhysRevB.104.144412]。相应的微观机制类似于导致对称非对角交换相互作用的机制（因为它涉及直接和配体介导的交换路径的组合），但在传统的拉曼散射的Loudon-Fleury理论中完全出乎意料。因此，目前的实验验证要求在类似的系统与强自旋轨道耦合和多个交换路径的拉曼散射的激烈的重新评估。
We investigate the magnetic excitations of the hyperhoneycomb Kitaev magnetby means of inelastic Raman scattering. The spectra exhibit the coexistence of a broad scattering continuum and two sharp low-energy peaks at 2.5 and 3 meV, with a distinctive polarization dependence. While the continuum is suggestive of fractional quasiparticles emerging from a proximate quantum spin liquid phase, the sharp peaks provide the first experimental signature of the “non-Loudon- Fleury” one-magnon scattering processes proposed recently [Yanget al., Phys. Rev. B 104, 144412 (2021)2469-995010.1103/PhysRevB.104.144412]. The corresponding microscopic mechanism is similar to the one leading to the symmetric off-diagonal exchange interaction(because it involves a combination of both direct and ligand-mediated exchange paths) but is otherwise completely unexpected within the traditional Loudon-Fleury theory of Raman scattering. The present experimental verification therefore calls for a drastic reevaluation of Raman scattering in similar systems with strong spin-orbit coupling and multiple exchange paths.