Spin freezing induced giant exchange bias in a doped Hund's metal  

作　　者：Shunjiao Li Dan Zhao Jian Li Baolei Kang Min Shan Yanbing Zhou Xuyang Li Tao Wu Xianhui Chen 

机构地区：[1]Hefei National Research Center for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China [2]CAS Key Laboratory of Strongly Coupled Quantum Matter Physics,Department of Physics,University of Science and Technology of China,Hefei 230026,China [3]CAS Center for Excellence in Superconducting Electronics(CENSE),Shanghai 200050,China [4]Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China [5]Hefei National Laboratory,University of Science and Technology of China,Hefei 230088,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2025年第2期167-174,共8页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Key R&D Program of China(Grant No.2022YFA1602601);the National Natural Science Foundation of China(Grant Nos.12034004,12161160316,and 12325403);the Basic Research Program of the Chinese Academy of Sciences Based on Major Scientific Infrastructures(Grant No.JZHKYPT-2021-08);the CAS Project for Young Scientists in Basic Research(Grant No.YBR-048);the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800);the Fundamental Research Funds for the Central Universities。

摘　　要：Exchange bias(EB)is a fundamental phenomenon in widespread information technologies.However,a comprehensive understanding of its microscopic origin remains a great challenge.One key issue in the debate is the role of frustration and disorder in the EB mechanism,which motivates the exploration of the EB effect in spin glass(SG)systems.Here,in the SG state of Crdoped Hund's metal CsFe_(2)As_(2),we discover a giant EB effect with a maximum bias field of -2 T,which is almost two orders of magnitude larger than that of traditional alloy SGs.Our results indicate that the giant EB effect should originate from the exchange interactions at the natural boundaries between the tunable ferromagnetic-like(FM)regions around Cr dopants and the SG matrix,via which the FM spins are strongly pinned by the frozen spins in the SG matrix.In addition,the temperaturedependent and cooling-field-dependent EB behaviors could be interpreted well by the SG model with frustrated FM/SG boundaries,which provides an intuitive and explicit understanding of the impact of glassy parameters on the EB effect.All these results suggest that the correlated metals are promising directions for exploring the EB effect in the SG state.

关 键 词：Hund's metal spin glass exchange bias iron-based superconductor 

分 类 号：O469[理学—凝聚态物理]