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In this work, ballistic phonon transport in atomic chain nanostructures is investigated by atomic nonequilibrium Green's functions and embedded atom method. Bond length and strength modification in atomic chain (low-dimensional structure) was taken into consideration by using bond-order-length-strength correlation premise. We especially focus on the contact interface effects on phonon transmission and thermal conductance. It is found that the contact interfaces between an atomic chain and contact reservoir, i.e., neck region or buffer layers, play an important role in phonon transport. The more buffer layers the less thermal conductance. [ABSTRACT FROM AUTHOR]

The effect of surface bond reconstruction (SBR) of Si contact surfaces on phonon transport in Si atomic wire is investigated. Green’s function method is applied to calculate the thermal conductance and local heat currents. Results show that the phonon transport in atomic wires is enhanced significantly by SBR at the thermal contact surface. A blue shift for phonon transmission function is induced by the SBR. [ABSTRACT FROM AUTHOR]

Phonon transport in atomic wire coupled by two semi-infinite thermal contacts is investigated by atomic nonequilibrium Green’s functions. The effect on phonon transport due to anharmonicity in atomic wire and surface bond reconstruction of thermal contact is analyzed. It is found that surface bond reconstruction affects phonon transport significantly in the presence of anharmonicity. [ABSTRACT FROM AUTHOR]

The impact of bond order loss of surface atoms on thermal conductivity of cylindrical silicon nanowires has been examined using the isotropic elastic continuum model. A core-shell structure with a modified Young’s modulus in the surface skin of the wire has been used. Thermal conductivity is calculated from modified phonon dispersion relations based on recent developed bond-order-length-strength (BOLS) correlation. This work extends the previous linear approximation [Yeung et al. Phys. Rev. B 74, 155317 (2006)] to calculate the phonon dispersion relation of torsional mode and longitudinal mode using the nonlinear approach. A significant increase in thermal conductivity is found compared to the case without using BOLS correlation. [ABSTRACT FROM AUTHOR]