论文标题
Kitaev磁铁$β$ -Li $ _2 $ iro $ _3 $ y kitaev磁铁中的非阵阵拉曼散射的签名
Signatures of non-Loudon-Fleury Raman scattering in the Kitaev magnet $β$-Li$_2$IrO$_3$
论文作者
论文摘要
我们通过无弹性拉曼散射研究了Hyperhoneycomb Kitaev磁铁$β$ - $β$ - $β$ - $β$ - $β$ - $β$ - $β$ - $β$ - $β$ - $β$ - $β$ - $β$ - 这些光谱表现出宽阔的散射连续体和2.5 MeV和3 MeV的两个尖锐的低能峰的共存，具有独特的极化依赖性。虽然连续体暗示了从近距离量子自旋液相中出现的分数准粒子，但尖峰提供了最近提出的“非阵阵'单刺'一麦克农散射过程的第一个实验性特征，[物理学。修订版B 104，144412（2021）]。相应的显微镜机制类似于导致对称偏外交换相互作用$γ$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劳登 - 弗里里理论中，否则是完全意外的。因此，目前的实验验证要求在具有强旋转轨道耦合和多个交换路径的类似系统中对拉曼散射进行剧烈重新评估。
We investigate the magnetic excitations of the hyperhoneycomb Kitaev magnet $β$-$\text{Li}_2\text{IrO}_3$ by means of inelastic Raman scattering. The spectra exhibits a coexistence of a broad scattering continuum and two sharp low-energy peaks at 2.5 meV and 3 meV, with a distinctive polarization dependence. While the continuum is suggestive of fractional quasi-particles 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 [Phys. Rev. B 104, 144412 (2021)]. The corresponding microscopic mechanism is similar to the one leading to the symmetric off-diagonal exchange interaction $Γ$ (as 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.
