Extreme asymmetry of 90-degree domain walls in multilayered films of (Ga,Mn)(As,P)

We image the magnetic domain structure during remagnetization of MBE grown multilayered films of a diluted magnetic semiconductor (Ga,Mn)(As,P) with digital modulations of the phosphorus concentration. The samples show two in-plane easy magnetization axes corresponding to the <100> cubic and [110] uniaxial anisotropies, typical for the GaMnAs system. Their remagnetization occurs in two steps through the nucleation and growth of 90-degree domains. Unexpectedly, the domain boundaries align precisely with the easy axes in contrast to our micromagnetic calculations using the measured magnetic parameters of the samples. We discuss how such totally asymmetric Neel domain walls can appear due to Dzyaloshinskii-Moriya interactions enhanced by the multiple sharp interfaces in the multilayered films.