The Regulation Of Phonon Chirality In The One-dimensional Atomic Junction Model

In traditional physics,the phonon is widely considered to be linearly polar-ized and its angular momentum is zero.However,phonons with nonzero angu-lar momentum have been found recently,which means phonons can be circular polarized and they are chiral.The chiral plhonon was e.xperimentally verified by transient infrared spectroscopy in a monolayer tungsten diselenide.Ac:companied by the discovery of the chiral phonon,which can be widely applied to many field-s.such as,valley electronics,two dimensional materials,phonics,photothermal and photoelectricity conversion,and energy-saving information application,the phonon chirality has become one hot topic,and the manipulation of the phonon chirality will provide an another potential method for information technology.In this work,we manipulate phonon chirality through interface transmission via a one-dimensional atomic junction model by using the scattering boundary method.Due to the difference of phase change between two transverse direc-tions induced by the anisotropy at interface coupling,the phonon can be tuned between circular and linear polarization in the high-frequency range.Through a two-junction atomic model with an anisotropic center,we found that the phase change accumulates when the phonon transport through the interface material thus make it possible to tune phonon between different chirality in a medium-frequency range.The phase change linearly depends on the width of the interface material,while the transmission coefficient vibrates in a small range.To make the transmission coefficients along two directions be equal thus keep the outgoing phonon circularly polarized,we can connect,two interface materials with opposit e anisotropy,where the phasc-change difference for chirality tuning is adjusted by the difference of sizes of the two materials.We can tune phonon chirality through the model with a central diatomic part,where the phonon polarization can be kept circular.The energy gap can be used to block one of the two components along transverse directions thus to convert chiral phonons to be linearly polarized along a selected direction.Therefore,by using the atomic junetion model,we find that the phonon chirality can be well tuned through interfaces,which will be helpful in the future application of chiral phonons.