Interface Response Theory

Acoustic analogue of electromagnetically induced transparency and Autler–Townes splitting in pillared metasurfaces

“…In this calculation, the radius of the pillars is r = 25 µm and the height is h = 245 µm. As shown by the red line in figure 3, a transmission dip appears in the frequency domain [6,8] MHz associated with the monopolar (compressional) resonance of this pillar that locates at f = 7.19 MHz (see the real part of u z ), well isolated from other intrinsic resonances in this frequency domain. The compressional mode of the pillar can be excited by the incident A 0 Lamb wave dominated by the displacement component u z and emits the same A 0 Lamb wave.…”

“…Phononic crystals [1][2][3][4][5][6] and acoustic metamaterials [7][8][9][10] are artificial acoustic composite materials controlling elastic/ acoustic waves in novel ways and have received significant attention from a wide range of communities. Phononic crystals possess Bragg band gaps resulting from the destructive interference among inclusions/scatters when the working wavelength is in the order of the lattice parameter, with applications like wave guiding [11][12][13], filtering [14][15][16], acoustic lensing [17][18][19] and so on.…”

Bound in continuum states and induced transparency in mesoscopic demultiplexer with two outputs

“…The electronic transport in the mesoscopic structure presented in this work is performed within the framework of the interface response theory of continuous media. [49] The objective of this theory is to calculate the Green's function of a composite system containing a large number of interfaces that separate different homogenous media. The present theory allows us to perform the calculations of reflection and transmission coefficients as well as the dispersion relations.…”

“…The latter is formed by a linear superposition of the surface matrix elements g −1 i (MM) of any independent wire bounded by perfectly free interfaces with appropriate boundary conditions. [49] Hence, before treating the whole structure, it would be useful to know the Green surface elements of its elementary constituents, namely, the Green's function of a finite resonator of length d i (i = 1, 2) and semi-infinite leads. The Schrödinger equation describing the motion of an electron in a potential barrier V i (x) is given by…”

“…The theoretical results are obtained using the Green's function approach. [49] This method of calculation enables the deducing of dispersion relations as well as transmission and reflection coefficients. It is worth mentioning that in two recent papers, [50,51] we have demonstrated the possibility to realize magnonic and photonic demultiplexer circuits based on the EIT resonances.…”