Magnetic Anisotropy and Two-Fold Anisotropic Superconductivity in Sn₄Au Single Crystals

Abstract

We report comprehensive magnetotransport and magnetization studies of Sn₄Au single crystals, revealing a two-fold anisotropic superconducting state below T_c = 2.3 K. Through angle-resolved resistivity measurements and Ginzburg-Landau analysis, we determine an anisotropy parameter Γ = 1.26, originating from the layered non-centrosymmetric Aea2 structure. First-principles calculations yield magnetic anisotropy energy E* = -0.62, explaining the observed suppression of critical current density (J_c ≈ 1.3×10⁴ A/cm²) and moderate upper critical fields (H_c2^‖ = 970 Oe, H_c2^⊥ = 770 Oe). The correlation between crystallographic anisotropy and superconducting properties provides new insights for topological superconductor design.