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We study the ferromagnetic resonance (FMR) on a system consisting of a ferromagnetic (FM) film and an antiferromagnetic film. The FMR frequency and its linewidth were derived analytically and calculated numerically as a function of applied magnetic field and its angle, exchange anisotropy, strength, and angle of the stress anisotropy for single crystal FM films with, respectively, uniaxial or cubic magnetocrystalline anisotropies. The results show that the system with an applied or residual stress anisotropy has some symmetrical, or equivalent, directions of the hard and easy axes. This property is always destroyed by the asymmetrical shift caused by the exchange anisotropy. This fact will be helpful to the experimentalist in distinguishing between the stress and the exchange anisotropies. [ABSTRACT FROM AUTHOR]

We use the analogy between scattering of a wave from a potential, and the precession of a spin-half particle in a magnetic field, to gain insight into the design of an antireflection coating for electrons in a semiconductor superlattice. It is shown that the classic recipes derived for optics are generally not applicable due to the different dispersion law for electrons. Using the stability conditions we show that a Poisson distribution of impedance steps is a better approximation than is a Gaussian distribution. Examples are given of filters with average transmissivity exceeding 95% over an allowed band. [ABSTRACT FROM AUTHOR]

Presents a study that examined the electron transmission and bound state properties of a quantum wire with a sharp bend at arbitrary angle. Use of a bent wire in performing transistor action; Discussion on the manifestation of quantal effects in mesoscopic systems; Mode matching technique for a quantum wire bent at arbitrary angle.

It is shown that propagation around a circular bend in a quantum wire is well approximated by a one-dimensional problem with a square-well potential replacing the bend. Simple analytic expressions are obtained for the transmission and bound states. [ABSTRACT FROM AUTHOR]