Snapshots of particle distribution (red dots) on the x-z plane at time t = 10⁴Ω⁻¹, and the root mean square of z (blue solid curve) as a function of the radial direction x (centeredon the snow line location and in units of the gas pressure scale height H_g). We plot ∣z∣, while z takes either positive or negative values. We set α_acc = 10⁻², α_{D r} = 0 and τ_s = 10⁻³. The vertical mixing parameter in each panel is (a) α_Dz = 10⁻⁵, (b) α_{D z} = 10⁻³, and (c) α_Dz = 10⁻¹. The analytical estimates of the equilibrium particle scale height for each α_Dz are shown by the dashed green lines. The back reactions are not included for v_r (Λ = 1) and α_{D z} (K = 0). We injected the particles in the range of x = [−0.05, 0.05]H_g and z = [−0.1, 0.1]H_g.