Pairing phase favored by magnetic frustration

The interplay between magnetic frustration and pairing is investigated by adopting a BCS-like pairing mechanism on the frustratedJ1-J2Ising model on the square lattice. The ground-state and thermal phase transitions of the model are analyzed using a fermionic formulation within a CMF method. In this approach, the lattice system is divided into identical clusters, where the intracluster dynamic is exactly solved, and the intercluster interactions are replaced by self-consistent mean fields. We introduce a framework with two pairing couplings: an intracluster local coupling,<i>g</i>, which controls the electron pairing and its mobility within the clusters, and an intercluster coupling,<i>g</i>', which adjusts the pairing mechanism between clusters. Tuningg'/gallows evaluating how the pairing phase evolves from a weak pairing coupling between clusters (clustered system) to a strong one (g'→g, homogeneous system). In the range0⩽g'/g⩽1, we find that a gradual increase ing'/gfavors the pairing phase and induces a change in criticality. In particular, our results reveal the presence of tricriticality for a certain range ofg'/g. In addition, an increase in competing magnetic interactions weakens the magnetic orders, causing the pairing phase to occur at lower strengths of pairing interactions, especially wheng'=g. Therefore, our findings support that magnetic frustration favors the pairing phase, contributing to the onset of a superconducting state.