Search

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]

Exact analytical results expressed in terms of Bessel functions for the bandgaps, reflectance and transmittance of one-dimensional photonic crystals with a sawtooth refractive index profile on the period are derived, to our knowledge for the first time. This extends the set of exactly solvable models with periodic refractive indices. Asymptotic approximations to the above exact results have been also obtained. [ABSTRACT FROM AUTHOR]

In the paper under discussion, it was observed that the accuracy of WKB approximate binding energies for the exponential potential deteriorates as the energy increases, an apparent violation of the correspondence principle. We show that a careful application of the WKB approximation as it applies to the centrifugal barrier potential leads to improved approximate binding energies of the exponential potential. Our analysis supports the Friedrich and Trost "reflection phase" version of the WKB quantization condition. [ABSTRACT FROM AUTHOR]

Using binary photonic crystals as an example, it is shown in a physically transparent manner how to construct two independent Floquet-Bloch waves in lossless one-dimensional periodic structures. Particular attention is given to those special cases where only one Bloch wave develops inside the structure. [ABSTRACT FROM AUTHOR]

The recurrence relations of the angular momentum vector addition coefficients are interpreted as a tight-binding model of a one-dimensional potential. From this model we derive their semi-classical limits in a simple manner, treating separately large J≈L+S and small J≈ ∣L-S∣. The resulting picture makes their qualitative behavior transparent to beginners, without the use of advanced concepts. [ABSTRACT FROM AUTHOR]

First, two conditions are specified for the lowest order Wentzel–Kramers–Brillouin quantization rule to yield exact results. These rules are related to the periodic orbit decomposition of the quantum density of states. This approach is then applied to supersymmetric quantum mechanics. It leads to a new derivation of the result that shape-invariant potentials give exact results when the classical action is calculated with the square of the super potential, but without the Maslov index or the Langer correction.PACS Nos.: 03.65.Sq, 12.60.Jv [ABSTRACT FROM AUTHOR]

A correction to the article "Comment on Exactly Solvable Models to Illustrate Supersymmetry and Test Approximation Methods in Quantum Mechanics" that was published in a 2012 issue is presented.