近日，美国加州大学的Xiangfeng Duan&Kang L. Wang&Yu Huang及其研究团队取得一项新进展。经过不懈努力，他们揭示手性分子–TaS₂杂化超晶格中的非常规超导性。相关研究成果已于2024年6月26日在国际权威学术期刊《自然》上发表。

本文研究了手性分子插层TaS2杂化超晶格中的非常规超导性。这项研究揭示了一个非常大的面内上临界场B_c2,||，远超过泡利顺磁极限，研究人员在Little-Parks测量中有一个强大的π相移和一个无场超导二极管效应(SDE)。这些非常规超导性的实验特征表明，晶体原子层和自组装手性分子层之间有趣的相互作用可能导致奇异的拓扑材料。该研究强调，混合超晶格可以通过将大量具有丰富物理性质的层状晶体与具有可设计结构基序和官能团的几乎无限变化的分子相结合，为人工量子材料奠定一条通用的道路。

据悉，手性超导体是一类独特的非常规超导体，其中复杂的超导序参量在动量空间中顺时针或逆时针旋转，代表了具有固有时间反演对称性破缺(TRSB)的拓扑非平凡系统，并直接影响拓扑量子计算。固有超导体在自然界中极为罕见，仅有少数如UTe₂、UPt₃和Sr₂RuO₄等备受争议的例子。非中心对称超导体中可能存在手性超导，尽管这种非中心对称在典型的固态超导体中并不常见。另外，既无镜像对称也不具有反演对称的手性分子得到了广泛的研究。研究人员认为将手性分子掺入常规超导体晶格中可以引入非中心对称性，从而有助于实现手性超导。

附：英文原文

Title: Unconventional superconductivity in chiral molecule–TaS₂ hybrid superlattices

Author: Wan, Zhong, Qiu, Gang, Ren, Huaying, Qian, Qi, Li, Yaochen, Xu, Dong, Zhou, Jingyuan, Zhou, Jingxuan, Zhou, Boxuan, Wang, Laiyuan, Yang, Ting-Hsun, Sofer, Zdenk, Huang, Yu, Wang, Kang L., Duan, Xiangfeng

Issue&Volume: 2024-06-26

Abstract: Chiral superconductors, a unique class of unconventional superconductors in which the complex superconducting order parameter winds clockwise or anticlockwise in the momentum space, represent a topologically non-trivial system with intrinsic time-reversal symmetry breaking (TRSB) and direct implications for topological quantum computing. Intrinsic chiral superconductors are extremely rare, with only a few arguable examples, including UTe₂, UPt₃ and Sr₂RuO₄ . It has been suggested that chiral superconductivity may exist in non-centrosymmetric superconductors, although such non-centrosymmetry is uncommon in typical solid-state superconductors. Alternatively, chiral molecules with neither mirror nor inversion symmetry have been widely investigated. We suggest that an incorporation of chiral molecules into conventional superconductor lattices could introduce non-centrosymmetry and help realize chiral superconductivity. Here we explore unconventional superconductivity in chiral molecule intercalated TaS₂ hybrid superlattices. Our studies reveal an exceptionally large in-plane upper critical field B_c2,|| well beyond the Pauli paramagnetic limit, a robust π-phase shift in Little–Parks measurements and a field-free superconducting diode effect (SDE). These experimental signatures of unconventional superconductivity suggest that the intriguing interplay between crystalline atomic layers and the self-assembled chiral molecular layers may lead to exotic topological materials. Our study highlights that the hybrid superlattices could lay a versatile path to artificial quantum materials by combining a vast library of layered crystals of rich physical properties with the nearly infinite variations of molecules of designable structural motifs and functional groups.

DOI: 10.1038/s41586-024-07625-4

Source: https://www.nature.com/articles/s41586-024-07625-4