Dipolar coupling and multidomain states in perpendicularly polarized nanostructures

Stripe states in multilayer systems with perpendicular polarization are investigated by analytical calculations within a general continuum approach, applicable to ferromagnetic, ferroelectric, or ferroelastic nanoscale superlattices. The competition between the long-range depolarization effect and short-range interlayer couplings can stabilize monodomain states and unusual stripe phase ground states with antiparallel polarization in adjacent layers. Geometric parameters of stable stripe domain states and the phase transitions lines between single domain states, aligned and antialigned stripe states have been derived. The theory is applied to analyze multidomain states and phase transitions in antiferromagnetically coupled multilayers [CoPt]/Ru.