比莱尔t-J-J_{} 模型和磁介导配对在压力尼基酸盐La_{3}Ni_{2}O_{7}中
Xing-Zhou Qu1,2, Dai-Wei Qu1,2, Jialin Chen2,3
1Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
Physical review letters
|February 2, 2024
概括
研究人员使用张量网络方法在酸盐La_{3}Ni_{2}O_{7}中发现了强大的超导性. 层间磁性合介导s波超导,提供对高过渡温度材料的见解.
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
- 量子材料 量子材料是一种量子材料.
背景情况:
- 酸超导体La_{3}Ni_{2}O_{7}的发现为研究非传统超导提供了新的前沿.
- 这种材料在压力下表现出高过渡温度 (约80K).
研究的目的:
- 通过使用先进的计算技术,研究La_{3}Ni_{2}O_{7}的双层t-J-J_{}模型中的超导 (SC) 顺序和配对机制.
- 为了确定超导的性质和强度,以及其温度依赖性.
主要方法:
- 最先进的张量网络方法,包括大规模密度矩阵重规范化组 (DMRG) 和无限预测纠对状态 (iPEPS) 计算.
- 使用触点空间张量重规范化组 (TSRG) 模拟来分析温度演变.
主要成果:
- 一个强大的s波超导顺序通过介于层间磁性合被确定.
- 发现了与Luttinger参数K_{SC}1和强对应强度Δ[over ̄]_{z}∼O(0.1的代数对应关系.
- 估计了高超导温度T_{c}^{*}/J∼O(0.1),这表明由于层间的旋转交换,对联显著增强.
结论:
- 双层t-J-J_{}模型准确地捕获了La_{3}Ni_{2}O_{7}中的强大的超导性.
- 层间磁性合在介导超导性方面发挥着至关重要的作用,类似于在超冷原子系统中的观测.
- 这项研究为高过渡温度基酸超导体的配对机制提供了重要的见解.
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