Suppression of coherent thermal transport in quasiperiodic graphene-hBN superlattice ribbons

Nanostructured superlattices are promising for novel electronic devices due to adjustable physical properties. Periodic superlattices facilitate coherent phonon transport due to constructive interference at the boundaries between materials. It is possible to induce a crossover from coherent to incoherent transport by adjusting the superlattice period. We have observed such crossover in periodic graphene-hBN nanoribbons as the length of individual domains increased. In general, transport properties are dominated by translational symmetry and the presence of unconventional symmetries leads to unusual transport characteristics. We performed non-equilibrium molecular dynamics simulations to investigate phonon heat transport in graphene-hBN superlattices following the Fibonacci quasiperiodic sequence. We show that the quasiperiodicity can suppress coherent phonon transport in these superlattices, and attribute this behavior to the increasing number of interfaces per unit cell as the generation increases, hindering phonon coherence. The suppression of coherent thermal transport enables a higher degree of control on heat conduction at the nanoscale, and shows potential for application in the design of novel thermal management devices.