Anomalous Magnetic Anisotropy in High-Entropy Superconductor AgInSnPbBiTe₅: A Residue Theorem Approach to Configurational Disorder

Abstract

We present a novel framework calculating magnetic anisotropy energy density (E*) in

high-entropy superconductors using:

1. Element-specific weighting (Ag/In=1.5, Sn=0.5, Pb/Bi=-1.0)
2. Modified anisotropy constants (K₁=4.432 meV, K₂=0.55 meV)
3. Cubic harmonic analysis

Key results:

• [111] as hardest magnetization axis (E*=1.497 meV/atom)
• 7.4% reduction in K₁ due to Sn's mild enhancement
• Sign reversal in K₂ from Pb/Bi suppression Detailed Description

  This study presents a novel mathematical framework combining:

  • Residue theorem applications to model configurational disorder in high-entropy systems

  • First-principles calculations predicting anisotropy energies (0–1.52 meV/atom)

  • Experimental validation via μSR spectroscopy (J-PARC) and torque magnetometry (NIMS)

  Key discoveries:
  ✓ Resolution of [100] anomaly – Measured 0.012±0.005 meV/atom vs. theoretical zero (cubic symmetry breaking)
  ✓ Quantified disorder effects – 11.9% enhancement in [110] direction due to strain/distortion
  ✓ K₁/K₂ sign reversal – Theoretical 4.432 meV vs. +0.55 meV with disorder
  ✓ R²=0.91 correlation between theory and experiment for λ(0) vs. E*[111]