Surface waves and mode conversion at a surface coated with an elastic heavy layer

A surface wave of frequency lying within bulk band of transverse waves is found in an elastic medium coated with a thin layer endowed with a surface mass density, surface Young's modulus and surface bending modulus. The wave is a particular case of surface resonance with infinite lifetime. In materials with negative Poisson's ratio (auxetics) the wave exists even for coating material with zero bending modulus, whereas with positive Poisson's ratio it requires the surface bending modulus to be larger than the surface Young's modulus. The manifestation of this wave in the reflection coefficient seems promising for fabrication of devices showing monochromator properties.