Date:	Wed, February 14, 2018
Time:	14:15
Place:	Research I Seminar Room

Abstract: The most important characteristic of a wave propagation is the dispersion equation describing the dependencies between time and spatial frequencies (wave numbers). For a given structure and a given kind of waves, the dispersion equation is fixed. In various applications, e.g. in noise control systems, in a producing of various insulators, or in a tuning of global models of fluid motions (ocean and atmosphere), it is necessary to modify existing dispersion equations to change the properties of a wave propagation. It can be achieved by using different procedures: from an insertion of various inclusions with different material properties into the initial matrix upto an application of artificial dissipative operators into the numerical schemes.

In the talk, we consider the acoustic wave propagation in 1D piezoelectric crystal. The dispersion equation is a simple linear dependence between the frequency and the wave number. After connecting the crystal to the 2D electrical network of variable capacitors, we can obtain very unusual and tunable dispersion diagrams which allows us to use this structure as, e.g., a high-efficiency acoustic filter/insulator. We present analytic results describing dispersion equations for surface and volume acousto-electric waves and show the wave simulations. The talk is based on the papers:

1) Dispersion spectrum of acoustoelectric waves in 1D piezoelectric crystal coupled with 2D infinite network of capacitors; J. Appl. Phys., 123, 044902 (2018); A. A. Kutsenko, A. L. Shuvalov, and O. Poncelet

2) Tunable effective constants of the one-dimensional piezoelectric phononic crystal with internal connected electrodes; J. Acoust. Soc. Am., 137 (2), pp. 606-616 (2015); A. A. Kutsenko, A. L. Shuvalov, O. Poncelet, A. N. Darinskii