Two-dimensional atomic localization induced by squeezed vacuum effect for β = 0 and Φ = 0. Other parameters are chosen as γ₁ = γ₂ = 1, Ω₁ = Ω₂ = 10, (a) N = 0; (b) N = 0.1; (c) N = 0.2; (d) N = 0.6.