Evolution of low-energy spin dynamics in the electron-doped high-transition-temperature superconductor Pr 0.88 LaCe 0.12 CuO 4-δ
Evolution of low-energy spin dynamics in the electron-doped high-transition-temperature superconductor Pr 0.88 LaCe 0.12 CuO 4-δ
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DOI：
10.1103/physrevb.74.144514
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发表时间：
2006-08
影响因子：
3.7
通讯作者：
Stephen D. Wilson;Shiliang Li;P. Dai;W. Bao;Jae-Ho Chung;H. J. Kang;Seung-Hun Lee;S. Komiya;Y. Ando;Q. Si
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文献类型：
--
作者：
Stephen D. Wilson;Shiliang Li;P. Dai;W. Bao;Jae-Ho Chung;H. J. Kang;Seung-Hun Lee;S. Komiya;Y. Ando;Q. Si
利用非弹性中子散射研究了电子掺杂铜酸盐Pr0.88LaCe0.12CuO4-Delta(PLCCO)从非超导反铁磁(AF)态到最佳掺杂超导体(T-c约24K)的低能自旋动力学演化。在低掺杂样品中，自旋激发的低温、低能响应与AF相的存在相耦合，而对于接近最佳T-c的样品，低能磁响应表现出对样品温度不敏感的自旋涨落。这种低能激发的演化与PLCCO相图中一个量子临界点的影响是一致的，该临界点与静态AF有序性的抑制有关。对实验数据进行了标度分析，讨论了量子临界动力学对观测激发谱的影响。
We use inelastic neutron scattering to explore the evolution of the low energy spin dynamics in the electron-doped cuprate Pr0.88LaCe0.12CuO4-delta (PLCCO) as the system is tuned from its nonsuperconducting, as-grown antiferromagnetic (AF) state into an optimally doped superconductor (T-c approximate to 24 K) without static AF order. The low-temperature, low-energy response of the spin excitations in underdoped samples is coupled to the presence of the AF phase, whereas the low-energy magnetic response for samples near optimal T-c exhibits spin fluctuations surprisingly insensitive to the sample temperature. This evolution of the low-energy excitations is consistent with the influence of a quantum critical point in the phase diagram of PLCCO associated with the suppression of the static AF order. We carried out scaling analysis of the data and discuss the influence of quantum critical dynamics in the observed excitation spectrum.