近日，美国宾夕法尼亚州立大学帕克分校Chang, Cui-Zu团队揭示了化学计量的FeTe是超导体。相关论文于2026年4月1日发表于《自然》杂志上。

铁基超导体（FeSCs）是一类迷人的材料，其中多个电子能带和强反铁磁（AFM）关联是竞争基态（包括反铁磁性、电子向列性和非常规超导电性）的关键要素。FeTe与其具有相同结构的超导对应物FeSe不同，长期以来被认为是一种没有超导性的反铁磁金属。

研究组利用分子束外延（MBE）生长FeTe薄膜，并在Te气氛下进行生长后退火。通过自旋极化扫描隧道显微镜和谱学（STM/S）研究，我们发现在生长的FeTe薄膜中，反铁磁有序是由破坏理想1:1化学计量比的间隙Fe原子诱导的。值得注意的是，通过Te退火去除这些间隙Fe原子，可以得到化学计量比的FeTe薄膜，该薄膜没有反铁磁有序，反而表现出约13.5 K临界温度的强超导电性。库珀对隧穿、零电阻和迈斯纳效应的观测进一步证实了这一超导态。

因此，该结果表明，化学计量比的FeTe本质上是一种超导体，推翻了其是反铁磁金属的长期观点。这项工作阐明了FeTe基异质结构中超导电性的起源，并展示了化学计量比控制在理解铁基超导体中反铁磁性与超导电性竞争方面的重要性。

附：英文原文

Title: Stoichiometric FeTe is a superconductor

Author: Yan, Zi-Jie, Wang, Zihao, Xia, Bing, Paolini, Stephen, Chan, Ying-Ting, Dihingia, Nikalabh, Rong, Hongtao, Xiao, Pu, Halanayake, Kalana D., Song, Jiatao, Gowda, Veer, Hickey, Danielle Reifsnyder, Wu, Weida, Yu, Jiabin, Hirschfeld, Peter J., Chang, Cui-Zu

Issue&Volume: 2026-04-01

Abstract: Iron-based superconductors (FeSCs) are a fascinating family of materials in which several electronic bands and strong antiferromagnetic (AFM) correlations are key ingredients for competing ground states1,2,3,4,5,6, including antiferromagnetism, electronic nematicity and unconventional superconductivity. FeTe, unlike its superconducting isostructural counterpart FeSe, has long been considered an AFM metal sans superconductivity7,8,9. Here we use molecular-beam epitaxy (MBE) to grow FeTe films and perform post-growth annealing under a Te flux. By performing spin-polarized scanning tunnelling microscopy and spectroscopy (STM/S), we demonstrate that the AFM order in as-grown FeTe films is induced by interstitial Fe atoms that disrupt the ideal 1:1 stoichiometry. Notably, the removal of these interstitial Fe atoms through Te annealing yields stoichiometric FeTe films that show no AFM order and instead exhibit robust superconductivity with a critical temperature of about 13.5K. This superconducting state is further confirmed by the observation of Cooper-pair tunnelling, zero electrical resistance and the Meissner effect. Therefore, our results demonstrate that stoichiometric FeTe is inherently a superconductor, overturning a long-held view that it is an AFM metal. This work clarifies the origin of superconductivity in FeTe-based heterostructures10,11,12,13,14,15 and demonstrates the importance of stoichiometry control in understanding the competition between antiferromagnetism and superconductivity in FeSCs.

DOI: 10.1038/s41586-026-10321-0

Source: https://www.nature.com/articles/s41586-026-10321-0