Anisotropy Energy and Superconducting Properties in High-Entropy Alloy Nb₃(Al,Sn,Ge,Ga,Si) Superconductors: A Theoretical and Experimental Correlation Study

High-entropy alloy (HEA) superconductors exhibit unique properties due to configurational disorder. In this study, we investigate the anisotropy energy (E₁*) in A15-type Nb₃(Al,Sn,Ge,Ga,Si) superconductors using a microscopic model, correlating it with experimental upper critical fields (H_c₂) and transition temperatures (T_c). Calculations for crystallographic directions (1,0,0), (1/√2,1/√2,0), and (1/√3,1/√3,1/√3) reveal that higher configurational entropy reduces anisotropy, enhancing H_c₂. A strong correlation (R² = 0.98) between E₁* and H_c₂ validates the model. These findings highlight the potential of HEAs to tailor superconducting performance through entropy-driven anisotropy modulation.