In a type-II superconductor between H_c1 and H_c2, magnetic flux penetrates as quantized vortices (Φ₀ = h/2e ≈ 2.07×10⁻¹⁵ Wb each). Repulsion between vortices drives them into a triangular (Abrikosov) lattice. The density of vortices scales as B/Φ₀.
Applied Field
H_c1Mixed stateH_c2
H_c1/H_c2 = ln(κ)/(2κ²). Each vortex core has radius ξ (coherence length), magnetic screening radius λ (penetration depth), κ = λ/ξ.