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The understanding and modeling of inelastic scattering of thermal phonons at a solid/solid interface remain an open question. We present a fully quantum theoretical scheme to quantify the effect of anharmonic phonon-phonon scattering at an…

Mesoscale and Nanoscale Physics · Physics 2021-05-26 Yangyu Guo , Zhongwei Zhang , Marc Bescond , Shiyun Xiong , Masahiro Nomura , Sebastian Volz

In this work, we use a combination of first-principles calculations under the density functional theory framework and heat transport simulations using the atomistic Green's function (AGF) method to quantitatively predict the contribution of…

Mesoscale and Nanoscale Physics · Physics 2017-03-01 Sridhar Sadasivam , Ning Ye , James Charles , Kai Miao , Joseph P. Feser , Tillmann Kubis , Timothy S. Fisher

We present the results of classical molecular dynamics simulations to assess the relative contributions to interfacial thermal conductance from inelastic phonon processes at the interface and in the adjacent bulk materials. The simulated…

We study the role of anharmonicity at interfaces with an added intermediate layer designed to facilitate interfacial phonon transport. Our results demonstrate that while in the harmonic limit the bridge may lower the conductance due to…

We numerically investigate thermal transport at solid-solid interfaces with graded intermediate layers whose masses vary exponentially from one side to the other. Using Non-Equilibrium Green's Function and Non-Equilibrium Molecular Dynamics…

Interfacial thermal resistance arises challenges for the thermal management as the modern semiconductors are miniatured to nanoscale. Previous studies found that graded mass distribution in interface can maximumly enhance the interfacial…

Materials Science · Physics 2023-06-28 Lina Yang , Baosheng Yang , Baowen Li

A new formalism for extracting the modal contributions to thermal interface conductance with full inclusion of anharmonicity is presented. The results indicate that when two materials are joined a new set of vibrational modes are required…

Materials Science · Physics 2014-07-25 Kiarash Gordiz , Asegun Henry

We investigate the anharmonic phonon scattering across a weakly interacting interface by developing a quantum mechanics-based theory. We find that the contribution from anharmonic three-phonon scatterings to interfacial thermal conductance…

Mesoscale and Nanoscale Physics · Physics 2022-02-23 Hangbo Zhou , Gang Zhang , Jian-Sheng Wang , Yong-Wei Zhang

The coherent quantum effect becomes increasingly important in the heat dissipation bottleneck of semiconductor nanoelectronics with the characteristic size shrinking down to few nano-meters scale nowadays. However, the quantum mechanical…

Mesoscale and Nanoscale Physics · Physics 2020-11-18 Yangyu Guo , Marc Bescond , Zhongwei Zhang , Mathieu Luisier , Masahiro Nomura , Sebastian Volz

We consider the problem of heat transport by vibrational modes (conduction) between Langevin thermostats connected by a central device. The latter is anharmonic and can be subject to large temperature differences and thus be out of…

Materials Science · Physics 2021-12-15 Keivan Esfarjani

We present an approach to calculate ballistic phonon transport that combines the atomistic Green's function (AGF) method with ab initio results. For the inter atomic potential we use the harmonic approach. The equilibrium positions of the…

Materials Science · Physics 2011-11-11 M. Bachmann , M. Czerner , S. Edaldati-Boostan , C. Heiliger

The anharmonicity of atomic motion limits the thermal conductivity in crystalline solids. However, a microscopic understanding of the mechanisms active in strong thermal insulators is lacking. In this letter, we classify 465 experimentally…

Materials Science · Physics 2023-06-14 Florian Knoop , Thomas A. R. Purcell , Matthias Scheffler , Christian Carbogno

We theoretically explore the influence of end-group chemistry (bond stiffness and mass) on the interfacial thermal conductance at a gold-alkane interface. We accomplish this using the Non-Equilibrium Green's Function (NEGF) coupled with…

Mesoscale and Nanoscale Physics · Physics 2018-09-14 Jingjie Zhang , Carlos A. Polanco , Avik W. Ghosh

We study the nonlinear interfacial thermal transport across atomic junctions by the quantum self-consistent mean field (QSCMF) theory based on nonequilibrium Green's function approach; the QSCMF theory we propose is very precise and matches…

Statistical Mechanics · Physics 2013-10-15 Lifa Zhang , Juzar Thingna , Dahai He , Jian-Sheng Wang , Baowen Li

Metal-semiconductor contacts are a pillar of modern semiconductor technology. Historically, their microscopic understanding has been hampered by the inability of traditional analytical and numerical methods to fully capture the complex…

Materials Science · Physics 2016-04-13 Daniele Stradi , Umberto Martinez , Anders Blom , Mads Brandbyge , Kurt Stokbro

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 phonon transmission function that…

Mesoscale and Nanoscale Physics · Physics 2017-11-15 Sridhar Sadasivam , Umesh V. Waghmare , Timothy S. Fisher

Compositionally graded interfaces in power electronic devices eliminate dislocations, but they can also decrease thermal conduction, leading to overheating. We quantify the thermal resistances of GaN/AlN graded interfaces of varying…

Materials Science · Physics 2019-03-27 Ambroise van Roekeghem , Bjorn Vermeersch , Jesús Carrete , Natalio Mingo

The calculations of thermal conductivity requires to know anharmonic properties of the crystal. For this purpose a non-perturbative anharmonic theory is applied, which do not make use of the potential energy expansion over atomic…

Materials Science · Physics 2023-01-06 Krzysztof Parlinski

Phonon-phonon interaction is systematically studied by nonequilibrium Green's function (NEGF) formulism in momentum space at finite temperatures. Within the quasi-particle approximation, phonon frequency shift and lifetime are obtained from…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yong Xu , Jian-Sheng Wang , Wenhui Duan , Bing-Lin Gu , Baowen Li

We report the first ever accurate theoretical prediction of thermal conductance of any material interface. Thermal interfacial conductance of aluminum (Al)-sapphire ({\alpha}-Al2O3) interface along crystal directions (111) Al || (0001)…

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