Hidden magnetic memory via CDW defects: Interplay of superconductivity, charge density waves, and Ising spin-orbit coupling

Transition metal dichalcogenide provide a rich platform to explore the coexistence of superconductivity and charge density waves (CDWs) under the influence of strong Ising spin-orbit coupling. Additionally, the weak van der Waals coupling between layers allows the engineering or growth of stacks of different 2D materials with competing orders, such as magnetism. Here, we demonstrate how defects in an incommensurate CDW, interacting with magnetic puddles, can give rise to hidden magnetic memory effects, even in the absence of a net spin magnetization. Furthermore, we show that the onset of superconductivity amplifies the magnetization signal, making it detectable via experimental techniques such as SQUID. We discuss how this mechanism may explain the spontaneous vortex phase detected in 4Hb-TaS2, offering new insights into the underlying physics of this puzzling observation.