Phononic conductance of quasi-one-dimensional waveguides with an atomic hole defect

A theoretical approach based on the matching method has been developed to investigate the local phonon density of states (DOS) and the coherent phonon transmission near the atomic hole defect. The model system containing the defect is composed of three monatomic triple parallel chains, with atomic hole defect introducing them in the central chain. The matching method is used, in the harmonic approximation, to calculate the local Greenʹs functions for the irreducible set of sites that constitute the inhomogeneous perturbed domain. The model system is studied for different cases of elastic hardening and softening in the perturbed zone. The purpose is to investigate how the local dynamics can respond to changes in the microscopic environment on the perturbed domain. The analysis of the total phonon conductance spectra and the densities of vibration states identify characteristic features and demonstrate the central role of the atomic hole defect localized in the perfect structure and the possible use, of them, as filters of phonon.