Stop bands in periodic and random media

Wave Motion and Stop-Bands in Pipes with Helical Characteristics Using Wave Finite Element Analysis

Pipes are widely used in many industrial and mechanical applications and devices. Although there are many different constructions according to the specific application and device, these can show helical pattern, such as spiral pipes, wire-reinforced pipes/shells, spring-suspension, and so on. Theoretical modelling of wave propagation provides a prediction about the dynamic behavior, and it is f...

Theoretical analysis of acoustic stop bands in two-dimensional periodic scattering arrays.

This paper presents a theoretical analysis of the recently reported observation of acoustic stop bands in two-dimensional scattering arrays [Robertson and Rudy, J. Acoust. Soc. Am. 104, 694 (1998)]. A self-consistent wave scattering theory, incorporating all orders of multiple scattering, is used to obtain the wave transmission. The band structures for the regular arrays of cylinders are comput...

Conduction bands in classical periodic potentials

The energy of a quantum particle cannot be determined exactly unless there is an infinite amount of time in which to perform the measurement. This paper considers the possibility that ∆E, the uncertainty in the energy, may be complex. To understand the effect of a particle having a complex energy, the behavior of a classical particle in a one-dimensional periodic potential V (x) = − cos(x) is s...

Coupled-mode stop bands of acoustic phonons in semiconductor superlattices.

Polarization Stop Bands in Chiral Polymeric Three-Dimensional Photonic Crystals

Chiral 3D photonic crystals are an interesting subclass of 3D photonic crystals. For example, large complete 3D photonic bandgaps have been predicted for high-index-contrast silicon square-spiral structures; corresponding experiments using glancing-incidence deposition, interference lithography, or direct laser writing have been published. In addition to complete gaps or stop bands, theory also...