Transport and thermoelectric signatures of Ising superconductivity and charge density wave in the misfit layered compound(SnS)1.15TaS2.

Misfit layered compounds based on transition metal dichalcogenides (TMDs) provide a rich platform for exploring emergent quantum phases, such as superconductivity and charge density wave (CDW) order. While many parent TMD compounds host both superconductivity and CDW, their misfit analogs often preserve only superconductivity. In this work, we present a comprehensive investigation of the misfit compound(SnS)1.15TaS2, a promising candidate for exhibiting both Ising-like superconductivity and a weak CDW. Through electrical transport and thermoelectric measurements, we find that the in-plane upper critical fieldHc2(T=0)significantly exceeds the Pauli paramagnetic limit, consistent with Ising superconductivity. Hall measurements reveal a notable reduction in carrier density below 50 K, suggesting the onset of CDW order. Seebeck and Hall data further indicate dominant n-type carriers, and suggest that while charge transfer from the SnS layer is minimal, cross-substitutional doping between Sn and Ta atoms may play an important role in modifying the Fermi surface. Our findings demonstrate that charge transfer predominantly influences CDW formation, whereas Ising superconductivity is robust against it, offering new insights into the interplay between structural motifs and electronic phases in misfit TMD materials.