The model use to study electromagnetic metamaterials in transverse electric mode was modified to study the pressure distribution in an acoustic metamaterial in a two dimensional geometry. An electromagnetic wave of 30 GHz in transverse magnetic mode at normal incidence propagating through a two dimensional isotropic semi infinite double negative metamaterial slab of 640×830 cells embedded in free space with low loss damping frequency 108s-1 was studied by finite difference time dependent method with Yee’s algorithm with an explicit leapfrog scheme. The multiple cycle m-n-m pulses generating beams were used as sources. The simulations for refractive indices n=-1 and n=-16 at different time steps are presented. For n=-1, the sub-wavelength imaging is apparent, diverging the waves from source into two sources, one inside and the other outside the slab. The reverse propagation is much more significant for showing that the group velocity is much larger inside the metamaterial by the closely packed wave front, making the continuation of the wave pattern much more significant through the metamaterial into the normal space.
International Letters of Chemistry, Physics and Astronomy (Volume 65)
S.M. Premarathna and K.A.I.L. Wijewardena Gamalath, "Simulation of Isotropic Acoustic Metamaterials", International Letters of Chemistry, Physics and Astronomy, Vol. 65, pp. 43-52, 2016