Tuning the polarized quantum phonon transmission in graphene nanoribbons

TL;DR

This paper demonstrates how to tune phonon transmission in graphene nanoribbons using isotope barriers, antidots, and boundary conditions, enabling control over thermal transport properties at the nanoscale.

Contribution

It introduces a method to precisely control phonon transmission in graphene nanoribbons through engineered structures and boundary conditions, advancing thermal management techniques.

Findings

Partial fixed boundary conditions restrict in-plane phonon modes at low energy.

Antidot and isotope arrangements diminish out-of-plane phonon transmission.

Periodic antidot arrays create sharp dips in transmission at predefined frequencies.

Abstract

We propose systems that allow a tuning of the phonon transmission function T($\omega$) in graphene nanoribbons by using C$^{13}$ isotope barriers, antidot structures, and distinct boundary conditions. Phonon modes are obtained by an interatomic fifth-nearest neighbor force-constant model (5NNFCM) and T($\omega$) is calculated using the non-equilibrium Green's function formalism. We show that by imposing partial fixed boundary conditions it is possible to restrict contributions of the in-plane phonon modes to T($\omega$) at low energy. On the contrary, the transmission functions of out-of-plane phonon modes can be diminished by proper antidot or isotope arrangements. In particular, we show that a periodic array of them leads to sharp dips in the transmission function at certain frequencies $\omega_{\nu}$ which can be pre-defined as desired by controlling their relative distance and size. With this, we demonstrated that by adequate engineering it is possible to govern the magnitude of the ballistic transmission functions T$(\omega)$ in graphene nanoribbons. We discuss the implications of these results in the design of controlled thermal transport at the nanoscale as well as in the enhancement of thermo-electric features of graphene-based materials.