Buckling-mediated phase transitions in nano-electromechanical phononic waveguides

Freeform Phononic Waveguides

We employ a recently introduced class of artificial structurally-disordered phononic structures that exhibit large and robust elastic frequency band gaps for efficient phonon guiding. Phononic crystals are periodic structures that prohibit the propagation of elastic waves through destructive interference and exhibit large band gaps and ballistic propagation of elastic waves in the permitted fre...

Nano-Electromechanical Optoelectronic Tunable Lasers

Quantitative measurements of phase transitions in nano- and glassy materials

Novel approaches to the collection and treatment of total x-ray scattering using high energy (> 65 keV) x-ray beams and area detectors allow in situ studies of unprecedented precision to be performed on nano-crystalline (n) and glassy materials at extremes of pressure (p) and temperature (T). Gradual structural transitions in glasses, liquids and nano-materials occurring via continuous changes ...

Elastic wave propagation along waveguides in three-dimensional phononic crystals

We investigate theoretically using the finite difference time domain method acoustic wave propagation along waveguides in three-dimensional phononic crystals constituted of lead spherical inclusions on a face-centered cubic lattice embedded in an epoxy matrix. The transmission spectra of the perfect phononic crystal for transverse and longitudinal acoustic waves are shown to depend strongly on ...

Finite element analysis of surface modes in phononic crystal waveguides

The study of surface modes in phononic crystal waveguides in the hypersonic regime is a burgeoning field with a large number of possible applications. By using the finite element method, the band structure and the corresponding transmission spectrum of surface acoustic waves in phononic crystal waveguides generated by line defects in a silicon pillar-substrate system were calculated and investi...