Ma Xueying, Li Keyi, Hou Shaoshuai, Mei Helin, Dong Yiwen, Tan Mingshu, Xie Mingtai, Ren Wei, Jiang Xingdong, Li Zhiwei, Zhang Anmin, Zhang Qingming
Lanzhou University, School of Physical Science and Technology, Key Laboratory of Quantum Theory and Applications of MoE, Lanzhou 730000, China.
Institute of Physics, Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
Phys Rev Lett. 2025 Jun 27;134(25):256002. doi: 10.1103/zhlp-4gdv.
The complex interplay between superconductivity, nematicity, and magnetism in iron-based superconductors remains a significant challenge in understanding its high-temperature superconductivity. Despite that numerous experiments aim at revealing the underlying mechanisms for superconductivity and nematicity by varying multiple tuning parameters, the inherent entanglement of these parameters complicates the isolation of the fundamental factors that drive the transitions. Here, by introducing a novel hydrothermal treatment to FeSe, we are able to effectively reduce interstitial Fe without altering the crystal structure and magnetic properties. This treatment results in a notable increase in carrier density and mobility, simultaneously enhancing both superconducting and nematic transition temperatures. Combining our experimental results with previous investigations, we reveal distinct pocket-influenced mechanisms: superconducting order is primarily influenced by electron pockets, while nematic order is driven by hole pockets. The results demonstrate the independent mechanisms of superconductivity and nematicity in FeSe, offering new perspectives on high-temperature superconductivity.
铁基超导体中超导电性、向列性和磁性之间复杂的相互作用，仍然是理解其高温超导性的一个重大挑战。尽管众多实验旨在通过改变多个调节参数来揭示超导电性和向列性的潜在机制，但这些参数的内在纠缠使得驱动转变的基本因素的分离变得复杂。在这里，通过对FeSe引入一种新颖的水热处理方法，我们能够在不改变晶体结构和磁性的情况下有效减少间隙铁。这种处理导致载流子密度和迁移率显著增加，同时提高了超导转变温度和向列转变温度。将我们的实验结果与先前的研究相结合，我们揭示了不同的口袋影响机制：超导序主要受电子口袋影响，而向列序则由空穴口袋驱动。结果证明了FeSe中超导电性和向列性的独立机制，为高温超导性提供了新的视角。
