Role of Magnetic Anisotropy Energy (E) in Determining the Superconducting Transition Temperature of Sn₄Au*

This work establishes the quantitative relationship between magnetic anisotropy energy (E*) and superconducting transition temperature (T_c) in Sn₄Au single crystals. Through experimental data analysis and theoretical modeling, we demonstrate that the measured E* = -0.62 leads to a 5% suppression of T_c compared to the isotropic case, while producing the observed two-fold anisotropy in upper critical fields (Γ = 1.26). These findings provide a framework for designing anisotropic superconductors.