Measurement of Magnetic Excitations in the Two-Dimensional Antiferromagnetic Sr2CuO2Cl2 Insulator Using Resonant X-Ray Scattering: Evidence for Extended Interactions
Measurement of Magnetic Excitations in the Two-Dimensional Antiferromagnetic Sr2CuO2Cl2 Insulator Using Resonant X-Ray Scattering: Evidence for Extended Interactions
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DOI：
10.1103/physrevlett.105.157006
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发表时间：
2010-10-08
影响因子：
8.6
通讯作者：
Grioni, M.
中科院分区：
文献类型：
--
作者：
Guarise, M.;Dalla Piazza, B.;Grioni, M.
我们测量了自旋为1/2的二维反铁磁绝缘体Sr 2CuO 2Cl 2（SCOC）中磁激发的动量依赖关系.我们确定了一个单一的自旋波功能和多磁连续，不同的偏振依赖性。自旋波在区域边界点（pi，0）和（pi/2，pi/2）之间显示出大的（70 meV）色散。采用一个扩展的t-t '-t'-U单带Hubbard模型，我们发现显着的电子跳跃超越最近邻铜离子，扩展的磁相互作用的指示。在（π，0）处的谱线形状表明SCOC中的相当大的量子效应，并且可能更普遍地在铜酸盐中。
We measured the momentum dependence of magnetic excitations in the model spin-1/2 2D antiferromagnetic insulator Sr2CuO2Cl2 (SCOC). We identify a single-spin-wave feature and a multimagnon continuum, with different polarization dependences. The spin waves display a large (70 meV) dispersion between the zone-boundary points (pi, 0) and (pi/2, pi/2). Employing an extended t-t'-t ''-U one-band Hubbard model, we find significant electronic hopping beyond nearest-neighbor Cu ions, indicative of extended magnetic interactions. The spectral line shape at (pi, 0) indicates sizable quantum effects in SCOC and probably more generally in the cuprates.