电子合的高过渡温度超导体Nd2-xCexCuO4+/-delta中的旋转相关性
E M Motoyama1, G Yu, I M Vishik
1Department of Physics, Stanford University, Stanford, California 94305, USA.
Nature
|January 12, 2007
概括
电子化酸盐中的高温超导性可能无法与远程反铁磁共存. 相反,一个量子临界点将这些现象联系起来,与旋转相关性驱动伪间隙.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 量子磁力 量子磁力 量子磁力
背景情况:
- 高过渡温度 (高T(c)) 超导性经常出现在反铁磁相附近,这表明磁刺激可能在配对中发挥作用.
- 了解二维反铁磁旋转相关的兴奋剂和温度依赖,对于阐明这种关系至关重要.
- 像Nd2-xCexCuO4+/-delta (NCCO) 等被电子合的酸盐表现出一个不对称的相图,其中反铁磁性进一步扩展并与超导性重叠.
研究的目的:
- 为了研究长距离反铁磁性和超导性在电子合铜酸盐中的共存.
- 探索超导性开始时量子相变的性质.
- 确定这些材料中伪间隙现象的起源.
主要方法:
- 无弹性磁性中子散射测量是在用电子合剂测试的酸盐上进行的.
- 分析的重点是反铁磁自旋相关性的兴奋剂和温度依赖.
- 与关于旋转相关性和伪间隙的理论建议进行比较.
主要成果:
- 证据表明,这些材料中没有真正的远程反铁磁性和超导性并存.
- 在超导电的出现时,确定了一个磁量子临界点,表明了奇特的量子相位过渡.
- 伪间隙现象与旋转相关性积累有关,与理论预测一致.
结论:
- 这项研究挑战了远距离反铁磁性和高T (c) 超导性在电子兴奋酸盐中直接共存的概念.
- 一个量子临界点,而不是共存,似乎决定了这些电子相之间的过渡.
- 旋转相关性被确定为电子合材料中伪间隙背后的驱动机制.
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