Preformed Cooper pairs in a triclinic iron pnictide superconductor

IF 6.4 1区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Science China Physics, Mechanics & Astronomy Pub Date : 2025-02-21 DOI:10.1007/s11433-024-2596-6

Zezhong Li, Wenshan Hong, Honglin Zhou, Xiaoyan Ma, Uwe Stuhr, Kaiyue Zeng, Long Ma, Ying Xiang, Huan Yang, Hai-Hu Wen, Jiangping Hu, Shiliang Li, Huiqian Luo

{"title":"Preformed Cooper pairs in a triclinic iron pnictide superconductor","authors":"Zezhong Li, Wenshan Hong, Honglin Zhou, Xiaoyan Ma, Uwe Stuhr, Kaiyue Zeng, Long Ma, Ying Xiang, Huan Yang, Hai-Hu Wen, Jiangping Hu, Shiliang Li, Huiqian Luo","doi":"10.1007/s11433-024-2596-6","DOIUrl":null,"url":null,"abstract":"<div>Electron pairing along with phase coherence generates superconductivity below the critical temperature (Tc). In underdoped high-Tc cuprates, these two quantum phenomena may occur at separate temperatures, which was lately confirmed in the quasi-two-dimensional (quasi-2D) iron chalcogenide superconductors. Here, we report a systematic investigation on the pre-pairing behavior in a triclinic iron pnictide superconductor (Ca0.85La0.15)10(Pt3As8)(Fe2As2)5 with Tc ≈ 30 K, where the superconductivity is quasi-2D manifested by the Berezinskii-Kosterlitz-Thouless behaviors. Inelastic neutron scattering experiments unambiguously reveal a spin resonance peak around ER = 13 meV in the superconducting state, but its intensity continuously decreases when warming up across Tc, accompanied with an anomaly around T* ≈ 45 K in spin correlations, and a suppression by an in-plane magnetic field persisting to the same temperature. Below T*, a significant Nernst signal and a reduction of density of states at the Fermi level are also observed. These results suggest that the precursor of spin resonance is highly related to the preformed Cooper pairs driven by phase fluctuations, much like the pseudogap case in cuprates.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 4","pages":""},"PeriodicalIF":6.4000,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Science China Physics, Mechanics & Astronomy","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s11433-024-2596-6","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHYSICS, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

Electron pairing along with phase coherence generates superconductivity below the critical temperature (T_c). In underdoped high-T_c cuprates, these two quantum phenomena may occur at separate temperatures, which was lately confirmed in the quasi-two-dimensional (quasi-2D) iron chalcogenide superconductors. Here, we report a systematic investigation on the pre-pairing behavior in a triclinic iron pnictide superconductor (Ca_0.85La_0.15)₁₀(Pt₃As₈)(Fe₂As₂)₅ with T_c ≈ 30 K, where the superconductivity is quasi-2D manifested by the Berezinskii-Kosterlitz-Thouless behaviors. Inelastic neutron scattering experiments unambiguously reveal a spin resonance peak around E_R = 13 meV in the superconducting state, but its intensity continuously decreases when warming up across T_c, accompanied with an anomaly around T* ≈ 45 K in spin correlations, and a suppression by an in-plane magnetic field persisting to the same temperature. Below T*, a significant Nernst signal and a reduction of density of states at the Fermi level are also observed. These results suggest that the precursor of spin resonance is highly related to the preformed Cooper pairs driven by phase fluctuations, much like the pseudogap case in cuprates.

查看原文本刊更多论文

三斜铁镍超导体中的预成形库珀对

电子对与相相干在临界温度（Tc）以下产生超导性。在欠掺杂的高tc铜酸盐中，这两种量子现象可能在不同的温度下发生，最近在准二维（准二维）硫系铁超导体中得到了证实。本文系统研究了Tc≈30 K的三斜铁镍超导体（Ca0.85La0.15）10(Pt3As8)(Fe2As2)5的预偶行为，其超导性为准二维，表现为Berezinskii-Kosterlitz-Thouless行为。非弹性中子散射实验明确表明，在超导状态下，在ER = 13 meV附近存在自旋共振峰，但随着温度的升高，其强度不断降低，自旋相关在T*≈45 K附近出现异常，并且在相同温度下受到面内磁场的抑制。在T*以下，还观察到一个显著的能司特信号和费米能级态密度的减小。这些结果表明，自旋共振的前驱体与由相位波动驱动的预形成的库珀对高度相关，很像铜酸盐中的赝隙情况。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Science China Physics, Mechanics & Astronomy PHYSICS, MULTIDISCIPLINARY-

CiteScore

10.30

自引率

6.20%

发文量

4047

审稿时长

3 months

期刊介绍： Science China Physics, Mechanics & Astronomy, an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, and published by Science China Press, is committed to publishing high-quality, original results in both basic and applied research. Science China Physics, Mechanics & Astronomy, is published in both print and electronic forms. It is indexed by Science Citation Index. Categories of articles: Reviews summarize representative results and achievements in a particular topic or an area, comment on the current state of research, and advise on the research directions. The author’s own opinion and related discussion is requested. Research papers report on important original results in all areas of physics, mechanics and astronomy. Brief reports present short reports in a timely manner of the latest important results.