Ballistic phonon thermal transport across topologically structured nanojunctions on Gold wires

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 88; pp. 97 - 103
• Main Authors: Belhadi, M., Khater, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2017
• Subjects: Ballistic transport; Heat conduction; Phonon states and bands, normal modes and phonon dispersion; Quantum wires; Heat conduction; Phonon states and bands, normal modes and phonon dispersion; Quantum wires; Ballistic transport
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2016.12.009

We investigate the coherent phonon thermal transport at low temperatures in Gold nanowires, in order to study the effects of scattering on the lattice thermal conductivity. Three types of shaped joint nanostructures are employed in our calculation. We present a detailed study of the thermal conductance as a function of the temperature for different shaped joint. This is done by solving the phonon Boltzmann transport equation in the ballistic regime and calculating the transmission rates of the vibration modes through the consideration of the phonon group velocity modification in the system. The transmission properties are calculated by use of the matching method in the harmonic approximation with nearest and next nearest neighbor force constants. The results show that the transmission probabilities depend on the type of joint nanostructure. The pronounced fluctuations of the transmission spectra as a function of the frequency can be understood as Fano resonances. It is also found that the behavior of the thermal conductance versus temperature is qualitatively different for different nanostructures and depends sensitively on the width of the shaped joint. •Ballistic phonon thermal transport across structured nanojunctions on Gold wires is calculated.•A detailed study for different shaped joint nanostructures is presented.•The matching method is used in accordance with Landauer-Buttiker formalism.•The thermal conductance is different for different nanostructures and depends on the width of the joint.