Spin dynamics and resonant inelastic x-ray scattering in chromium with commensurate spin-density wave order
Spin dynamics and resonant inelastic x-ray scattering in chromium with commensurate spin-density wave order
复制标题
具有相应自旋密度波阶的铬中的自旋动力学和共振非弹性 X 射线散射
DOI：
10.1103/physrevb.87.134418
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发表时间：
2013
影响因子：
3.7
通讯作者：
and Takami Tohyama
中科院分区：
文献类型：
--
作者：
Koudai Sugimoto;Zhi Li;Eiji Kaneshita;Kenji Tsutsui;and Takami Tohyama
基于由3，4轨道组成的多带Hubbard模型，研究了铬原子的自旋动力学和公度自旋密度波阶的边共振非弹性X射线散射（RIXS）.在SDW平均场近似下得到基态，用随机相位近似计算了动态横、纵向自旋极化率。我们发现在非弹性中子散射中看到的集体自旋波激发几乎不衰减到0.6eV。在能量之上，激发与预期的单个粒子-空穴激发重叠，导致宽光谱权重。另一方面，集体自旋波激发在RIXS光谱有一种趋势，掩盖了大的光谱重量来自粒子空穴激发与各种轨道通道。这与非弹性中子散射相反，在非弹性中子散射中，只有选定的对角轨道通道对谱权重有贡献。然而，如果分辨率足够高，将来可能在RIXS实验中检测到自旋波激发。
We theoretically investigate spin dynamics and-edge resonant inelastic x-ray scattering (RIXS) of chromium with commensurate spin-density wave (SDW) order, based on a multiband Hubbard model composed of 3and 4orbitals. Obtaining the ground state with the SDW mean-field approximation, we calculate the dynamical transverse and longitudinal spin susceptibility by using random-phase approximation. We find that a collective spin-wave excitation seen in inelastic neutron scattering hardly damps up to0.6 eV. Above the energy, the excitation overlaps individual particle-hole excitations as expected, leading to broad spectral weight. On the other hand, the collective spin-wave excitation in RIXS spectra has a tendency to be masked by large spectral weight coming from particle-hole excitations with various orbital channels. This is in contrast with inelastic neutron scattering, where only selected diagonal orbital channels contribute to the spectral weight. However, it may be possible to detect the spin-wave excitation in RIXS experiments in the future if resolution is high enough.