2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/120760We investigate the ground state competition at the transition from the spin unpolarized to spin ordered phase at filling factor $ν=2/3$ in single layer heterostructure and at $ν=2$ in double layer quantum well. To trace the quantum Hall phase we use the minimum in the dissipative conductivity $σ_{xx}$. We observe two different transition scenarios in two investigated situations. For one of them we propose a qualitative explanation, based on the domain structure evolution in the vicinity of the transition point. The origin for the second scenario, corresponding to the experimental situation at $ν=2$ in double layer 2DES, still remains unclear.4 pagesMesoscale and Nanoscale Physicstext