Thermal transport in S-shaped graphene nano-junctions

• The phonon transport property is investigated for S-shaped GNJs using Green's function method.
• The low frequency forbidden bands are sensitive to their periodic geometric shape of GNJs.
• The transmission spectrum of low frequency phonon shows forbidden frequency band, by changing the width W2 of the S-shaped GNJs
• With an increase in the number of period Nx, the phonon transmission is weakened.

By using nonequilibrium Green's function method, we study the phonon transport properties in S-shaped graphene nano-junctions (GNJs). Interesting transmission phenomenon is found. The transmission spectrum of low frequency phonon shows forbidden frequency band, by changing the width W2 of the S-shaped GNJs. These low frequency forbidden bands are sensitive to their periodic geometric shape of GNJs. These thermal transport phenomena can be explained by analyzing the phonon transmission coefficient. This paper illustrates the thermal transport mechanisms in the different S-shaped GNJs, and the results could provide significant physical models and theoretical validity in designing the thermal devices based on the GNJs.