Ultra-sharp oscillatory magneto-resistance in spatially confined La_0.3Pr_0.4Ca_0.3MnO₃ epitaxial thin films

Our investigations of magneto-transport properties of La_0.3Pr_0.4Ca_0.3MnO₃ manganite thin films of reduced dimensions revealed dramatic changes in R(θ), the dependence of resistivity on the angle between the magnetic field direction and the current direction, and consequently in the anisotropic magneto-resistance. A regular oscillatory  sin²θ form of R(θ) is replaced by a very sharp rectangular-shaped ones when the dimensions of the system become comparable to the size of the intrinsic electronic domains. We discuss possible mechanisms that could be responsible for these changes.