For a complex number z, let Re(z) denote the real part of z. Let 𝑆 be the set of all complex numbers z satisfying $$z^4 − \mid z\mid^4 = 4 𝑖 z^2$$, where $$i = \sqrt{−1}$$. Then the minimum possible value of $$\mid z_1 − z_2\mid^2$$, where $$z_1, z_2 \in S$$ with $$Re(z_1) > 0$$ and $$Re(z_2) < 0$$, is _____