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Effect of Electron-Phonon Coupling on Thermal Transport across Metal-Nonmetal Interface - A Second Look
The effect of electron-phonon (e-ph) coupling on thermal transport across
metal-nonmetal interfaces is yet to be completely understood. In this paper, we
use a series of molecular dynamics (MD) simulations with e-ph coupling effect
included by Langevin dynamics to calculate the thermal conductance at a model
metal-nonmetal interface. It is found that while e-ph coupling can present
additional thermal resistance on top of the phonon-phonon thermal resistance,
it can also make the phonon-phonon thermal conductance larger than the pure
phonon transport case. This is because the e-ph interaction can disturb the
phonon subsystem and enhance the energy communication between different phonon
modes inside the metal. This facilitates redistributing phonon energy into
modes that can more easily transfer energy across the interfaces. Compared to
the pure phonon thermal conduction, the total thermal conductance with e-ph
coupling effect can become either smaller or larger depending on the coupling
factor. This result helps clarify the role of e-ph coupling in thermal
transport across metal-nonmetal interface
Study of Thermal Properties of Graphene-Based Structures Using the Force Constant Method
The thermal properties of graphene-based materials are theoretically
investigated. The fourth-nearest neighbor force constant method for phonon
properties is used in conjunction with both the Landauer ballistic and the
non-equilibrium Green's function techniques for transport. Ballistic phonon
transport is investigated for different structures including graphene, graphene
antidot lattices, and graphene nanoribbons. We demonstrate that this particular
methodology is suitable for robust and efficient investigation of phonon
transport in graphene-based devices. This methodology is especially useful for
investigations of thermoelectric and heat transport applications.Comment: 23 pages, 9 figures, 1 tabl
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