Midinfrared absorption in YBa2Cu3O6: Evidence for a failure of spin-wave theory for spin 1/2 in two dimensions : Evidence for a failure of spin-wave theory for spin 1/2 in two dimensions
Midinfrared absorption in YBa2Cu3O6: Evidence for a failure of spin-wave theory for spin 1/2 in two dimensions : Evidence for a failure of spin-wave theory for spin 1/2 in two dimensions
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YBa2Cu3O6 中的中红外吸收：二维自旋 1/2 的自旋波理论失败的证据 : 二维自旋 1/2 的自旋波理论失败的证据
DOI：
10.1103/physrevb.62.12422
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发表时间：
2000
影响因子：
3.7
通讯作者：
T. Kopp
中科院分区：
文献类型：
--
作者：
M. Grüninger;D. van der Marel;A. Damascelli;A. Erb;T. Nunner;T. Nunner;T. Kopp;T. Kopp
详细研究了未掺杂和极低掺杂yba2cu3o6.0 δ在中红外范围内的光学电导率σ (ω)。我们收集了观测到的吸收的磁源的实验证据。主共振峰可以用自旋波理论计算的双像非加声子吸收谱很好地描述。但自旋波理论无法描述更高频率下的共振，且谱权随温度和掺杂而增加。这强调了量子涨落对于描述二维自旋1/2系统中的短波长磁激发的重要性。
The optical conductivity σ (ω) of undoped and very low doped YBa 2 Cu 3 O 6.0 δ is studied in detail in the midinfrared range. We collect experimental evidence for a magnetic origin of the observed absorption. The main resonance peak is well described by a bimagnon-plus-phonon absorption spectrum calculated within spin-wave theory. But spin-wave theory fails to describe further resonances at higher frequencies with significant spectral weight, which grows with both temperature and doping. This underlines the importance of quantum fluctuations for the description of short-wavelength magnetic excitations in a two-dimensional spin-1/2 system.