Concept of phonon pdf

Formulations of the phonon transport problem depend on the length scale of interest. At the bottom end of the scale is the atomistic description. There are fundamental reasons for going to the atomic … Expand. An atomistic Green 's function method is developed to simulate phonon transport across a strained germanium or silicon thin film between two semi-infinite silicon or germanium contacts.

A … Expand. While the atomistic Green's function AGF method has the potential to compute spectrally resolved phonon transport across interfaces, most prior formulations of the AGF method provide only the total … Expand.

Full quantification of frequency-dependent interfacial thermal conductance contributed by two- and three-phonon scattering processes from nonequilibrium molecular dynamics simulations. Understanding phonon transport across interfaces serves as a major tool to advance a diverse spectrum of fundamental and applied research. Unlike bulk materials, where the three-phonon scattering … Expand. Role of anharmonic phonon scattering in the spectrally decomposed thermal conductance at planar interfaces.

Materials Science, Physics. A detailed understanding of the vibrational heat transfer mechanisms between solids is essential for the efficient thermal engineering and control of nanomaterials. We investigate the frequency … Expand. Quantum thermal transport in nanostructures.

In this colloquia review we discuss methods for thermal transport calculations for nanojunctions connected to two semi-infinite leads served as heat-baths.

Our emphases are on fundamental … Expand. An approach is presented for the atomistic study of phonon transport in real dielectric nanowires via Green's functions. At the same time, the remarkably weak four-phonon collisions in compounds containing boron, carbon, and nitrogen help those materials retain high thermal conductivities. These insights into the interplay between three-phonon and four-phonon collisions give a fundamental understanding of phonon decay rates and thermal conduction in solids, and they inform computational schemes designed to interrogate these fundamental material properties.

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To address this, we have been improving access via several different mechanisms. The large thermal conductivity reductions even at K show that the lowest-order theory of phonon-phonon interactions is failing for many of these materials. The compounds are listed in ascending order of the mean LA-TA velocity ratio. Compounds with the largest velocity ratios have the A A A 2 selection rule activated.

However, unlike in Figs. It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4. Mode locking and mode competition in a nonequilibrium solid-state condensate. B 78 , Wouters, M. Synchronized and desynchronized phases of coupled nonequilibrium exciton-polariton condensates. B 77 , R Disorder, synchronization and phase locking in non-equilibrium Bose-Einstein condensates.

Kasprzak, J. Bose-Einstein condensation of exciton polaritons. Demokritov, S. Bose-Einstein condensation of quasi-equilibrium magnons at room temperature under pumping. Misochko, O. Transient Bose-Einstein condensation of phonons. A , Bose condensation of strongly excited longitudinal electric modes. A 26 , Griffin, A. Press Oktel, M. Internal waves and synchronized precession in a cold vapor. Nowik-Boltyk, P.

Spatially non-uniform ground state and quantized vortices in a two-component Bose-Einstein condensate of magnons. Long range coherence and the action of enzymes. Rayleigh-Jeans condensation of pumped magnons in thin-film ferromagnets. Sun, C. Observation of the kinetic condensation of classical waves. Li, F. Phase diagram for magnon condensate in yttrium iron garnet film. Masut, R. Spatial Bose-Einstein condensation. Dominici, L.

Real-space collapse of a polariton condensate. Nature Communications. Eichfeld, S. Rapid, non-destructive evaluation of ultrathin WSe2 using spectroscopic ellipsometry. APL Mat. Highly scalable, atomically thin WSe2 grown via metal-organic chemical vapor deposition.

ACS Nano 9 , Download references. We thank Y. Lin, A. Safriet, R. Naguy and M. McConney for help in preparing the experiment. We also acknowledge discussions with L. Levitov, I. Zaliznyak, D. Dorsey and A. Igor Altfeder, Andrey A. You can also search for this author in PubMed Google Scholar.

All authors contributed to analysis of results. Correspondence to Igor Altfeder. This work is licensed under a Creative Commons Attribution 4. Reprints and Permissions. Sci Rep 7, Download citation. Received : 21 July Accepted : 20 January Published : 22 February Anyone you share the following link with will be able to read this content:.

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Download PDF. Subjects Bose—Einstein condensates Two-dimensional materials. Abstract Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale.

Introduction The concept of phonons describes quantum behavior and elementary excitations of sound waves in solids 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , The construction of this curve involves summation of all standing wave modes across the 1 st Brillouin zone BZ : Figure 1: STM-based optical phonon detection setup. Full size image. Figure 4: STM Fourier transforms. Discussion All our experimental findings can be successfully explained by formation of coherent phonon quasi-bound states around intercalation defects.

Figure 6: Analysis of the contribution of cosine modes to standing wave patterns. Figure 7: Analysis of condensate droplets. Additional Information How to cite this article : Altfeder, I. References 1 Lui, C. Google Scholar 26 Manzano, G. Google Scholar 29 Chen, L. Google Scholar 56 Li, F. Acknowledgements We thank Y. Search websites, locations, and people. Enter keywords to search for news articles: Submit.

Browse By. Explained: Phonons. When trying to control the way heat moves through solids, it is often useful to think of it as a flow of particles. David L. Publication Date :.