Slow acoustic surface modes through the use of hidden geometry

AbstractThe acoustic surface modes supported by a partly covered periodic meander groove structure formed in an assumed perfectly rigid plate are investigated. This allows one to create a slower acoustic surface wave than can be achieved with the same uncovered meander structure. By changing the size of the uncovered section the phase and group speeds can be tuned. When the uncovered section of the meander structure is centred along the grooves then the distance along the grooves between neighbouring holes is the same on both sides of the structure so no band gap is observed at the first Brillouin zone boundary due to glide symmetry. This then gives quite linear dispersion. As the uncovered section’s position is moved away from the centre of the meander structure a band gap opens at the Brillouin zone boundary.

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A method for estimating the location of energy minima near the Brillouin zone boundary and its application to Gallium arsenide

Physics Letters A ◽

10.1016/0375-9601(69)90224-2 ◽

1969 ◽

Vol 29 (11) ◽

pp. 716-717 ◽

Cited By ~ 6

Author(s):

T.K. Gaylord ◽

T.A. Rabson

Keyword(s):

Gallium Arsenide ◽

Brillouin Zone ◽

Zone Boundary ◽

Brillouin Zone Boundary

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Nonlinear nonstationary equation of interaction between an electron beam and electromagnetic field near the Brillouin zone boundary

Radiophysics and Quantum Electronics ◽

10.1007/bf01039225 ◽

1984 ◽

Vol 27 (12) ◽

pp. 1099-1105 ◽

Cited By ~ 11

Author(s):

A. P. Kuznetsov ◽

S. P. Kuznetsov

Keyword(s):

Electromagnetic Field ◽

Electron Beam ◽

Brillouin Zone ◽

Zone Boundary ◽

Brillouin Zone Boundary ◽

Nonstationary Equation ◽

Nonlinear Nonstationary Equation

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Angular control of acoustic waves oblique incidence by phononic crystals based on Dirac cones at the Brillouin zone boundary

Physics Letters A ◽

10.1016/j.physleta.2017.12.014 ◽

2018 ◽

Vol 382 (6) ◽

pp. 423-427 ◽

Cited By ~ 2

Author(s):

Wen-Qiang Zhang ◽

Xin Zhang ◽

Fu-Gen Wu ◽

Yuan-Wei Yao ◽

Shui-Fang Lu ◽

...

Keyword(s):

Brillouin Zone ◽

Acoustic Waves ◽

Oblique Incidence ◽

Phononic Crystals ◽

Zone Boundary ◽

Brillouin Zone Boundary

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Photonic Band Structure of Nanochannel Glass Materials

MRS Proceedings ◽

10.1557/proc-431-449 ◽

1996 ◽

Vol 431 ◽

Author(s):

A. Rosenberg ◽

R. J. Tonucci ◽

H.-B. Lin

Keyword(s):

Band Structure ◽

Brillouin Zone ◽

Near Infrared ◽

Nearest Neighbor ◽

Dielectric Structure ◽

Zone Boundary ◽

Photonic Band Structure ◽

Brillouin Zone Boundary ◽

Photonic Band ◽

Good Agreement

AbstractWe demonstrate that nanochannel glass (NCG) materials are ideal for investigating twodimensional (2D) photonic band-structure effects. The NCG materials we have studied consist of triangular arrays of glass cylinders embedded in a glass matrix, having center-tocenter nearest-neighbor separations from 0.54 to 1.08 μm. The indices of refraction of the two glasses differ by less than 0.02 in the relevant spectral region. Narrow attenuation features occur whenever the dispersion relation for light propagating within such a periodic dielectric structure crosses a Brillouin zone boundary. The attenuations corresponding to the first Brillouin zone appear in the near-infrared (IR), at wavelengths between 1 and 3 μm, in good agreement with calculations.

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Tilt and acoustic instabilities in ABX 4, A 2 BX 4 and ABX 3 perovskite structure types: their role in the incommensurate phases of the organic–inorganic perovskites

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768105028879 ◽

2005 ◽

Vol 61 (6) ◽

pp. 616-626 ◽

Cited By ~ 18

Author(s):

Ian Peter Swainson

Keyword(s):

Brillouin Zone ◽

Three Dimensional ◽

Low Frequency ◽

Zone Boundary ◽

Brillouin Zone Boundary ◽

Perovskite Layer ◽

Modulated Phases ◽

Acoustic Instabilities ◽

Incommensurate Phases ◽

Zero Frequency

An examination of the tilt modes and other low-frequency modes is made for an isolated, untilted perovskite layer, which maps very simply to the ABX 4 perovskites. A sheet of pure tilts exists at the Brillouin Zone boundary at {ξ, ½, ζ}. An instability is also found at all wavevectors which can be described as continuously varying from pure tilts to pure layer displacements as a function of the wavevector. Analysis is extended by considering the stacking of layers in the I-centered A 2 BX 4-layer perovskites. The effect of freezing in the commensurate tilt required to generate the Cmca tilt system, pertinent to the modulated phases of propylammonium salts, is examined. The zero-frequency modes are restricted to two planes in the Brillouin Zone. All of the observed wavevectors associated with modulated phases, and the commensurately tilted propylammonium tetrachlorocadmate, are consistent with this calculation. The effect of full three-dimensional connectivity is briefly reviewed for the true ABX 3 perovskites. While pure tilt incommensurates appear to be hypothetically possible, they do not appear to have been observed to date.

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