Properties of phonons-quanta of the crystal lattice vibrations-in graphene have recently attracted significant attention from the physics and engineering communities. Acoustic phonons are the main heat carriers in graphene near room temperature, while optical phonons are used for counting the number of atomic planes in Raman experiments with few-layer graphene. It was shown both theoretically a...

2014 In the insulating spin-glass material EU0.4Sr0.6S, the transient E.S.R. absorption following a strong r.f. pulse has been studied at X band for T ~ Tg. The signal was found to depend strongly upon the experimental conditions (energy of the r.f. pulse, value of the driving magnetic field). At 4.2 K and with a weak perturbing r.f. energy (1 03BCJ), the recovery was exponential (03C4 ~ 40 ms)...

The phonon thermal conductivity of MOF-5, a metal-organic framework crystal with a phenylene bridge, is predicted between temperatures of 200 K and 400 K using molecular dynamics simulations and the Green–Kubo method. The simulations are performed using interatomic potentials obtained using ab initio calculations and experimental results. The predicted thermal conductivity of MOF-5 is low for a...

We make an adaptation of laser modelling equations to describe the behavior of a phonon laser (saser). Our saser consists of an AlGaAs/GaAs double barrier het-erostructure designed to generate an intense beam of transversal acoustic (T A) phonons. To study our system, we begin with a Hamiltonian that describes the decay of primary longitudinal optical phonons (LO 1) into secondary (LO 2) and T ...

The angular distribution after reflection at a cleaved NaF-liquid He interface of a collimated phonon beam incident from the helium at a grazing angle of incidence of ̂ 10° has been measured. The results suggest the existence of interface states which interact with only a part of the incident phonon spectrum. In the light of experiments which have been aarried out on the problem of phonon transm...

We carry out a detailed analysis of the short-wave semiclassical approximation for the linear equations of the elasticity in a smoothly inhomogeneous isotropic medium. It is shown that the polarization properties of the transverse waves are completely analogous to those of electromagnetic waves and can be considered as spin properties of optical phonons. In particular, the Hamiltonian of the tr...

The textbook thermophoretic force which acts on a body in a fluid is proportional to the local temperature gradient. The same is expected to hold for the macroscopic drift behavior of a diffusive cluster or molecule physisorbed on a solid surface. The question we explore here is whether that is still valid on a 2D membrane such as graphene at short sheet length. By means of a nonequilibrium mol...

Dynamics of photoinduced phase transitions in molecular conductors are reviewed from the perspective of interplay between correlated electrons and phonons. (1) The charge-transfer complex TTF-CA shows a transition from a neutral paraelectric phase to an ionic ferroelectric phase. Lattice phonons promote this photoinduced transition by preparing short-range lattice dimerization as a precursor. M...

One-dimensional crystals of passively-driven particles in microfluidic channels exhibit collective vibrational modes reminiscent of acoustic 'phonons'. These phonons are induced by the long-range hydrodynamic interactions among the particles and are neutrally stable at the linear level. Here, we analyze the effect of particle activity - self-propulsion - on the emergence and stability of these ...

The phonon structure of GaP quantum dots is studied using an atomistic potential model. The dot eigenmodes are obtained from a direct diagonalization of the dynamical matrix and classified using an efficient dual-space analysis method. Our calculations provide a theoretical explanantion for several experimental observations. ~1! Depending on the spatial localization, the phonon modes of dots ar...