Observation of Multi-gap Superconductivity and Anomalous transport properties in a misfit layered compound (PbS)_1.13TaS₂

Recent experimental studies on vdW/artificial heterostructures have dynamized the field of quantum materials which provide unique access to investigate various correlated quantum states. Stacking different layers leads to novel concerted effects such as charge redistribution, proximity effects and interfacial superconductivity which increase the functionality of such heterostructures. In this context, Misfit layered compounds (MLCs) have renewed interest as they are naturally occurring vdW heterostructures, feasible to experimental studies. The presence of two structural dissimilar sublattices in MLCs makes them the suitable platform to investigate several intriguing physical properties. In recent studies on (LaSe)_1.14NbSe₂ and (LaSe)_1.14(NbSe₂)₂, Ising spin-orbit coupling (SOC) protected superconductivity is observed, violating the Pauli limiting field which enables the possible emergence of Ising SOC in bulk materials.

In this work, I investigated the superconducting properties of successfully grown single crystals of (PbS)_1.13TaS₂ misfit compound. From magnetization and specific heat measurements bulk superconducting transition is observed with the critical temperature of T_c = 3.03(2) K. The estimated temperature variation of the upper critical field from resistivity measurement is fitted with the two-gap model, indicating multi-band superconductivity in (PbS)_1.13TaS₂. In addition, the occurrence of anomalous transport in (PbS)_1.13TaS₂, makes it a valuable candidate for searching non-trivial properties.