Unconventional superconductivity in chiral molecule-TaS 2 hybrid superlattices.

Chiral superconductors, a unique class of unconventional superconductors in which the complex superconducting order parameter winds clockwise or anticlockwise in the momentum space 1 , represent a topologically non-trivial system with intrinsic time-reversal symmetry breaking (TRSB) and direct implications for topological quantum computing 2,3 . Intrinsic chiral superconductors are extremely rare, with only a few arguable examples, including UTe 2 , UPt 3 and Sr 2 RuO 4 (refs.  4-7 ). It has been suggested that chiral superconductivity may exist in non-centrosymmetric superconductors 8,9 , 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 10 . Here we explore unconventional superconductivity in chiral molecule intercalated TaS 2 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 11 .