We have recently observed and simulated confined acoustic phonons in both thin silicon-on insulator films and in SOI membranes [1]. Since progress in silicon device technology is going through increasing use of silicon-on-insulator (SOI) as a strategic device material to increase the operation speed of integrated circuits [2] modifications in the phonon spectrum are of strategic interest to dev...

We study the depairing effect due to Coulomb interactions in NaxCoO2. We consider the electron-phonon coupling and the Coulomb interactions, and determine Tc for s-wave superconductivity by solving the linearized Eliashberg equation. When we consider shear phonons as well as breathing phonons, Tc is enhanced by Suhl-Kondo (SK) mechanism. Since SK mechanism is strong against Coulomb interactions...

Atomic substitution in alloys can efficiently scatter phonons, thereby reducing the thermal conductivity in crystalline solids to the "alloy limit." Using In0.53Ga0.47As containing ErAs nanoparticles, we demonstrate thermal conductivity reduction by almost a factor of 2 below the alloy limit and a corresponding increase in the thermoelectric figure of merit by a factor of 2. A theoretical model...

We study the effects of phonons on the tunneling of an atom between two surfaces. In contrast to an atom tunneling in the bulk, the phonons couple very strongly and qualitatively change the tunneling behavior. This is the first example of Ohmic coupling from phonons for a two-state system. We propose an experiment in which an atom tunnels from the tip of an scanning-tunneling microscope, and sh...

Coherent longitudinal-optical phonons are generated in semiconductor heterostructures. The coupling of the coherent, longitudinal-optic ~LO! phonons to collective carrier excitations oscillating parallel to the growth direction of GaAs/Al0.36Ga0.64As quantum wells is investigated with femtosecond time-resolution. This coupling is found to be weak for small well widths and evolves towards the bu...

Coherent acoustic phonons modulate optical, electronic and mechanical properties at ultrahigh frequencies and can be exploited for applications such as ultratrace chemical detection, ultrafast lasers and transducers. Owing to their large absorption cross-sections and high sensitivities, nanoplasmonic resonators are used to generate coherent phonons up to terahertz frequencies. Generating, detec...

We investigate the generation of acoustic phonons from electrostriction of optical waves in small core waveguides. We specifically consider simple step-index strip waveguides composed of silica or silicon in air, with sub-micron lateral dimensions. Such waveguides support one or a few optical modes, but a rich spectrum of acoustic phonons that becomes densely populated as the phonon frequency i...

The decoherence of a qubit coupled with the phonons of a finite-size lattice is investigated. The confined phonons no longer behave as a reservoir. They remain sensitive to the qubit so that the origin of the decoherence is twofold. First, a qubit-phonon entanglement yields an incomplete true decoherence. Second, the qubit renormalizes the phonon frequency resulting in fake decoherence when a t...

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Heat conduction by phonons is a ubiquitous process that incorporates a wide range of physics and plays an essential role in applications ranging from space power generation to LED lighting. Heat conduction has been studied for over two hundred years, yet many microscopic aspects of heat conduction have remained unclear in most crystalline solids, including which phonons carry heat and how natur...