三维量子格里菲斯奇点在散装铁-普尼化物超导体中的特征.
Shao-Bo Liu1, Congkuan Tian1,2, Yongqing Cai3,4
1International Center for Quantum Materials, School of Physics, Peking University, Beijing 100091, China.
National science review
|November 18, 2024
概括
研究人员在非传统的高温超导体中观察到了量子格里菲斯奇点 (QGS). 这一发现扩大了对3D超导系统和高温超导体中的QGS的理解.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 量子材料科学 量子材料科学
背景情况:
- 量子格里菲斯奇点 (Quantum Griffiths singularity,简称QGS) 是一种现象,在灭混乱的系统中,在量子相变 (QPT) 过程中观察到.
- QGS打破了传统的缩放不变性,导致了不同的动态临界指数.
- 虽然在低维的传统超导体和3D磁性系统中记录了QGS,但3D超导体和非传统的高温超导体 (高Tc SC) 中的QGS仍然不清楚.
研究的目的:
- 调查QGS在非传统的高TcSC中的存在和特征.
- 在这些材料中建立超导体-金属过渡 (SMT) 的量子相图.
主要方法:
- 在CaFe1-xNixAsF大批量单晶 (准二维和三维异型) 中实验性观察QGS.
- 应用垂直和平行磁场来诱导SMT.
- 描述QGS状态及其在高温下持久性的特征.
主要成果:
- 在近二维和三维异型非传统高TcSCs (CaFe1-xNixAsF,x <5%) 的SMT中观察到强大的QGS.
- 发现QGS状态持续长达5.3K.
- 建立了一个全面的量子相位图,划分由磁场诱导的3D异性质QGS.
结论:
- 该研究提供了QGS在3D超导系统和非传统的高Tc SC中普遍性的证据.
- 这些发现显著扩大了QGS现象的适用范围.
- 这项研究为理解复杂材料中的量子关键性开辟了新的途径.
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