Critical Temperature of Superconducting Magnetic Hybrid Systems

We study proximity systems made of coupled thin films with superconducting and magnetic ground states. We analyze how varying parameters of the magnetic component affects the superconducting critical temperature T_c of the entire system. Singlet Cooper pairs formed in the superconducting layer permeate into the magnetic material resulting in the generation of triplet pair correlations that may modify T_c. The critical temperature is calculated by solving Usadel’s equations using an involved transformation to an eigenvalue problem. The method is a generalization of previous work that enables us to include magnetic inhomogeneities. We apply the method to a trilayer SF₁F₂ where F₁ and F₂ have different magnetic properties. Specifically, we study the behavior of T_c as a function of the thickness and magnetization twisting angle of F₁ with respect to F₂.