Novel spin excitations in optimally electron-doped Pr0.89LaCe0.11CuO4
Novel spin excitations in optimally electron-doped Pr0.89LaCe0.11CuO4
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DOI：
10.1143/jpsj.75.093704
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发表时间：
2006-09-01
影响因子：
1.7
通讯作者：
Yamada, Kazuyoshi
中科院分区：
文献类型：
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作者：
Fujita, Masaki;Matsuda, Masaaki;Yamada, Kazuyoshi
为了研究磁激发谱的详细结构，我们对最佳电子掺杂的Pr（0.89）LaCe（0.11）CuO4（Tc = 25.5 K）进行了中子散射实验。定义明确的自旋激发存在到能量为ω的类似于180 meV，这与Wilson等人最近的观察结果一致。96（2006）157001]中描述的方法。在我们的实验中，更好的统计数据揭示了更精确的光谱结构。当能量增加到与60 meV相似的Ω（c）时，峰宽（kappa）显著增加，但在超过Ω（c）的高能区，峰宽几乎保持与能量无关。chi“（ω）在w = 6 meV处显示出尖锐的峰值，该峰值随着能量的增加而显著减小，直到最终在ω（c）附近没有观察到明确的磁信号。然而，一个广泛的磁峰在（π，π）再次出现超过Ω类似于100毫电子伏。我们讨论的自旋激发谱的性质，这是极大地不同于传统的自旋波激发与本地化的自旋。
To study the detailed structure of the magnetic excitation spectrum, we performed a neutron scattering experiment on optimally electron-doped Pr(0.89)LaCe(0.11)CuO4 (T-c = 25.5 K). Well-defined spin excitations existed up to an energy of omega similar to 180meV, which is consistent with the recent observation by Wilson et al. [Phys. Rev. Lett. 96 (2006) 157001] for the same cuprate with a different T-c. Better statistics in our experiment revealed a more precise structure of the spectrum. As the energy increased up to omega(c) similar to 60 meV, the peak width (kappa) markably increased, but in the high-energy region beyond omega(c) the width remained nearly independent of the energy. chi ''(omega) showed a sharp peak at w = 6 meV, which markably diminished as the energy increased until eventually a well-defined magnetic signal was not observed near omega(c). However, a broad magnetic peak at (pi, pi) reappeared beyond omega similar to 100 meV. We discuss the nature of the spin excitation spectrum, which is vastly different from that of a conventional spin wave excitation with localized spins.