نتایج جستجو برای: phonon dispersion

تعداد نتایج: 76044  

Journal: :journal of sciences islamic republic of iran 0

a theory is presented for the dispersion relations of the nonlinear phonon-polaritons arising when phonons are coupled to the electromagnetic waves in multilayered structures of nonlinear materials. the calculations are applied to a multilayered structure consisting of a thin film surrounded by semi-infinite bounding media where each layer may have a frequency dependent dielectric function and ...

A theory is presented for the dispersion relations of the nonlinear phonon-polaritons arising when phonons are coupled to the electromagnetic waves in multilayered structures of nonlinear materials. The calculations are applied to a multilayered structure consisting of a thin film surrounded by semi-infinite bounding media where each layer may have a frequency dependent dielectric function and ...

تشکری, حسن, نجاتی, عاطفه, کنجوری, فرامرز,

In this work, we calculated the phonon dispersion of GaNNTs (4,0) and (4,4) by quantum ESPRESSO package using Density Functional Theory (DFT), pseudo potentials, and plane wave self-consistent field (PWscf) method. For the purpose of lattice-dynamical calculation and phononic properties, we used PWscf and Phonon codes. The former produces the self-consistent electronic and all related computati...

Journal: :journal of sciences islamic republic of iran 0

we have calculated the phonon frequencies of kc1 along symmetry directions using an approach which is a combination of the frozen phonon and force constants methods. we also calculated griineisen parameters for all modes at x and l points in the brillouin zone. finally, the slope of acoustic dispersion curves around zone center were used to calculate the three independent elastic coefficients c...

فرقدان, روح اله, مسعودی نیا, فرشته,

This paper shows a theoretical study of the thermal properties of armchair grapehen nanoribbons in the presence of extended vacancies. Each graphene nanoribbons formed by superlattices with a periodic geometric structure, different size and symmetry of vacancies. The phonon dispersion, specific heat and thermal conductivity properties are described by a force-constant model and also by Landauer...

We have calculated the phonon frequencies of KC1 along symmetry directions using an approach which is a combination of the frozen phonon and force constants methods. We also calculated Griineisen parameters for all modes at X and L points in the Brillouin zone. Finally, the slope of acoustic dispersion curves around zone center were used to calculate the three independent elastic coefficien...

Journal: :Physical review letters 2006
M M de Lima M van der Poel P V Santos J M Hvam

We show that the coherent interaction between microcavity polaritons and externally stimulated acoustic phonons forms a tunable polariton superlattice with a folded energy dispersion determined by the phonon population and wavelength. Under high phonon concentration, the strong confinement of the optical and excitonic polariton components in the phonon potential creates weakly coupled polariton...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2005
Bin Liu J Goree

Phonons in a one-dimensional chain of charged microspheres suspended in a plasma were studied in an experiment. The phonons correspond to random particle motion in the chain; no external manipulation was applied to excite the phonons. Two modes were observed, longitudinal and transverse. The velocity fluctuations in the experiment are analyzed using current autocorrelation functions and a phono...

2002
Youping Chen James D. Lee

The phonon dispersion relations calculated by atomic model: shell model and ab initio, and by microcontinuum theory are introduced in this paper. It is found that both atomic models and microcontinuum theory can describe the common feature of phonon dispersion relation for the crystal having more than one atom per primitive cell and can give a good fit to the experimentally measured data. The o...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید