在PbSe0.5Te0.5中同时发生的压力诱导超导和光导过渡
Dongxuan Han1, Di Peng2,3, Sheng-Cai Zhu4
1Academy for Advanced Interdisciplinary Studies and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, P. R. China.
Advanced materials (Deerfield Beach, Fla.)
|December 31, 2024
概括
在高压下在PbSe0.5Te0.5中发现了超导和负光导 (NPC). 这些现象与结构变化和电子-声子相互作用有关,可以通过光或冷却来调节.
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
- 固态化学 固态化学
背景情况:
- 同时超导和负光导 (NPC) 是罕见的现象.
- 石素是具有可调节电子性质的多功能材料.
研究的目的:
- 研究在高压下PbSe0.5Te0.5中的超导和光导的共存和相互作用.
- 阐明导致这些现象的潜在机制和结构转变.
主要方法:
- 高压实验高达~40 GPa使用钻石天细胞.
- 超导测量 (Tc的确定).
- 光导度测量 (阳性和阴性模式).
- 用X射线衍射进行结构分析.
- 第一个原则的计算 (密度函数理论).
- 霍尔系数测量. 霍尔系数测量.
主要成果:
- 在压缩和解压缩下在PbSe0.5Te0.5中发现了超导和正光导 (PPC) 和NPC之间的过渡.
- 观察到可逆的结构转变 (3D Fm3m 2D Pnma 3D Pm3m).
- 超导率 (最大Tc ≈6.7K) 与NPC和Pnma到Pm3m在~18 GPa的过渡期相吻合.
- 增强的Tc ≈6.9K在保存的Pm3m阶段的解压过程中观察到.
- 第一个原则的计算表明,增强的PP杂交和电荷转移会影响电子-声子相互作用.
- 大厅测量显示光热效应改变载体度和移动性,导致PPC-NPC逆转.
结论:
- 同时的超导和光导过渡与金属Pm3m相密切相关.
- 通过光热效应增强的电子 - 声子相互作用,调解了超导和NPC.
- 超导和NPC是结构依赖的,可以通过照明或高压冷却来调节.
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