Figure 4
The phase diagram of the growth behavior for (a) 1 ≤ M ≤ 22, (b) the dense interaction regime 18 ≤ M ≤ 22, and (c) the sparse interaction regime 1 ≤ M ≤ 5. The partial bidirectionality expands the area of the diverging phase (filled circles). There exists an upper phase boundary (dotted line) at around 18 < M < 22 and a lower phase boundary (solid line) at around 1 ≤ M < 5. The upper boundary is asymmetric for the bidirectionality and there is an optimum bidirectionality for the growth rate at around P ~ 0.3. The finite phase (open circles) in the sparse connecting regime M < 5 remains within a range of small but finite bidirectionality. The area of the finite phase gradually decreases as a function of the increasing bidirectionality.
