近日，复旦大学的赵俊及其研究团队取得一项新进展。经过不懈努力，他们揭示加压三层La₄Ni₃O_10-δ单晶中的超导性。相关研究成果已于2024年7月17日在国际权威学术期刊《自然》上发表。

据悉，追求发现与铜基模型不同的新的高温超导体，对解释超导背后的机制具有深远意义，也可能实现新的应用。研究表明，压力的施加有效地抑制了三层镍酸La₄Ni₃O_10-δ单晶的自旋电荷序，导致在60.9GPa下超导性的出现，最高临界温度(T_c)约为30K。直流磁化率测量证实在T_c以下存在明显的抗磁响应，表明存在体积分数超过80%的体超导性。

在正常状态下，研究人员观察到一种奇怪的金属行为，其特征是线性温度依赖电阻延伸到300K。此外，观察到的层相关超导性暗示了镍酸盐特有的独特层间耦合机制，使它们在这方面有别于铜酸盐。这项研究发现为超导的基本机制提供了重要见解，同时也引入了一个新的材料平台来探索自旋-电荷序、平带结构、层间耦合、奇怪金属行为和高温超导之间复杂的相互作用。

附：英文原文

Title: Superconductivity in pressurized trilayer La₄Ni₃O_10-δ single crystals

Author: Zhu, Yinghao, Peng, Di, Zhang, Enkang, Pan, Bingying, Chen, Xu, Chen, Lixing, Ren, Huifen, Liu, Feiyang, Hao, Yiqing, Li, Nana, Xing, Zhenfang, Lan, Fujun, Han, Jiyuan, Wang, Junjie, Jia, Donghan, Wo, Hongliang, Gu, Yiqing, Gu, Yimeng, Ji, Li, Wang, Wenbin, Gou, Huiyang, Shen, Yao, Ying, Tianping, Chen, Xiaolong, Yang, Wenge, Cao, Huibo, Zheng, Changlin, Zeng, Qiaoshi, Guo, Jian-gang, Zhao, Jun

Issue&Volume: 2024-07-17

Abstract: The pursuit of discovering new high-temperature superconductors that diverge from the copper-based model has profound implications for explaining mechanisms behind superconductivity and may also enable new applications. Here our investigation shows that the application of pressure effectively suppresses the spin–charge order in trilayer nickelate La₄Ni₃O_10-δ single crystals, leading to the emergence of superconductivity with a maximum critical temperature (T_c) of around 30K at 69.0GPa. The d.c. susceptibility measurements confirm a substantial diamagnetic response below T_c, indicating the presence of bulk superconductivity with a volume fraction exceeding 80%. In the normal state, we observe a strange metal behaviour, characterized by a linear temperature-dependent resistance extending up to 300K. Furthermore, the layer-dependent superconductivity observed hints at a unique interlayer coupling mechanism specific to nickelates, setting them apart from cuprates in this regard. Our findings provide crucial insights into the fundamental mechanisms underpinning superconductivity, while also introducing a new material platform to explore the intricate interplay between the spin–charge order, flat band structures, interlayer coupling, strange metal behaviour and high-temperature superconductivity.

DOI: 10.1038/s41586-024-07553-3

Source: https://www.nature.com/articles/s41586-024-07553-3