Gap electroacoustic waves inPT-symmetric piezoelectric heterostructure near the exceptional point.

The spectral properties of gap electroacoustic waves in aPT-symmetric structure of piezoelectrics of symmetry class 6 mm separated by a gap are theoretically investigated. The spectra were calculated for lead germanate (non-zero transverse piezoactivity) and barium titanate (symmetry class 4 mm-zero transverse piezoactivity). It has been established that at a certain level of losses and gain in piezoelectrics, the symmetric and antisymmetric modes intersect. The intersection point determines the singular point of thePT-symmetric structure. Beyond this point, there is a violation of the symmetric and antisymmetric distribution of electric fields in the gap of the slotted structure of two identical piezoelectrics, which is confirmed by the calculation of the electric field profiles. It is shown that the dependence of the amplitude on the frequency at an exceptional point has an extremely narrow resonance peak, which opens up the possibility of creating supersensitive sensors based onPT-symmetric physical structures.

Hypersonic magnetoelastic waves in inhomogeneous structures.

This work focuses on the propagation of surface magnetoelastic waves in a inhomogeneous structure containing ferromagnetic layer of smooth and slowly variable thickness. The dispersion relation of magnetoelastic waves and the wave attenuation due to the thickness variation in the studied structure were analytically obtained. We found that the magnetoelastic resonance frequency is changed at different positions in this structure. Then proposed the idea of modifying the magnetic field to control the magnetoelastic resonance region, and finally considered the possible applications of this structure for signal processing.