Three‐dimensional photonic crystals are fabricated from block copolymers, forming a double gyroid network structure. Further processing produces three‐dimensionally nanoporous, freestanding materials (see Figure), and allows dielectric enhancement infiltration, which dramatically improve optical material properties. These etched provide path to highly effective via self‐assembly.

In this Letter we propose the use of hypersonic phononic crystals to control emission and propagation high frequency phonons. We report fabrication quality, single crystalline using interference lithography show that direct measurement their band structure is possible with Brillouin light scattering. Numerical calculations are employed explain nature observed modes. This work lays foundation for experimental studies and, more generally, phonon-dependent processes in nanostructures.

We demonstrate theoretically the simultaneous localization of photons and phonons in same spatial region by introducing lattice defects a periodic array dielectric/elastic material that exhibits gaps for both electromagnetic elastic waves. Transverse waves, pure shear mixed dilatation waves were simultaneously localized. The coexistent light sound can have strong influence on photon-phonon interactions (i.e., optical cooling) possibility dual acoustic-optical devices integrate management...

Abstract Interference lithography (IL) holds the promise of fabricating large‐area, defect‐free 3D structures on submicrometer scale both rapidly and cheaply. A stationary spatial variation intensity is created by interference two or more beams light. The pattern that emerges out distribution transferred to a light sensitive medium, such as photoresist, after development yields bicontinuous photoresist/air structure. Importantly, proper choice beam parameters one can control geometrical...

By transforming heat flux from particle to wave phonon transport, we introduce a new class of engineered material control thermal conduction. We show that rationally designed nanostructured alloys can lead fundamental approach for management, guiding as photonic and phononic crystals guide light sound, respectively. Novel applications these materials include waveguides, lattices, imaging, thermo-optics, diodes, cloaking.

Band structures of three dimensionally periodic bi- and tricontinuous cubic have been calculated using the plane-wave method for solving Maxwell's equations. In particular, we consider single primitive, diamond, gyroid, double diamond level surface families as examples such found in self-organizing systems. We also provide design guidelines creating three-dimensional photonic crystals with a complete band gap from block copolymer systems other

We show how to fabricate three basic photonic crystal structures with simple cubic, fcc, and bcc translational symmetry by interference lithography. The are fabricable the of beams launched from same half space. cubic structure is size scalable while fcc possesses two band gaps. Both these experimentally realized.

Abstract Thermal transport in nanostructures has attracted considerable attention the last decade but precise effects of surfaces on heat conduction have remained unclear due to a limited accuracy treatment phonon surface scattering phenomena. Here, we investigate impact phonon-surface distribution thermal energy across wavelengths and mean free paths Si SiGe nanowires. We present rigorous accurate description at predict analyse nanowire spectra for different diameters conditions. show that...

It is fascinating to think of the abstract beauty crystals, with countless atoms occupying precise positions on a lattice and giving rise perfect order high levels symmetry. Indeed, we need look no further than brilliant appearance extraordinary properties many precious gems witness consequences these atomic arrangements.

Interference lithography holds the promise of fabricating large-area, defect-free photonic structures on sub-micrometer scale both rapidly and cheaply. There is a need for procedure to establish connection between that are formed parameters interfering beams. also produce self-supporting three-dimensional bicontinuous structures. A generic technique correlating beams with symmetry elements present in resultant by level-set approach developed. particular space group ensured equating terms...

We study the effects of phonon boundary scattering on transport thermal energy in semiconductor thin films across multiple length scales and temperatures. use a model based kinetic theory processes that accurately calculates reduction mean free paths by including spatial location propagation direction phonons. investigate how effective resultant conductivities are reduced film scale surface roughness. The silicon germanium calculated for temperatures between 4 K 500 thicknesses from nano to...

Understanding thermal energy transport in polycrystalline semiconductors is important for the efficiency of electronic devices and thermoelectric materials. In this paper, we study reduction generated by shortening phonon mean free paths due to grain boundary scattering. We calculate conductivity polycrystals, from macro-to-nanograin sizes different temperatures, using a theoretical approach based on kinetic theory processes. The involves an exact expression that includes their directional,...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Martin Maldovan; Transition between ballistic diffusive heat transport regimes in silicon materials. Appl. Phys. Lett. 10 September 2012; 101 (11): 113110. https://doi.org/10.1063/1.4752234 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar...

Thermal transport at small length scales has attracted significant attention in recent years and various experimental theoretical methods have been developed to establish the reduced thermal conductivity. The fundamental understanding of how phonons move physical mechanisms behind nanoscale transport, however, remains poorly understood. Here we beyond conductivity calculations provide a rigorous comprehensive description phonon superlattices by solving Boltzmann equation using...