Full-spectrum thermal analysis in twisted bilayer graphene

It has been recently reported that a magic angle, i.e. 1.1 degrees, exists in twisted bilayer graphene which could lead to intrinsic unconventional superconductivity. Variations of the twisting angle between different graphene layers could lead to altered electronic band structures, which results in the peculiar superconductivity phenomenon. The effects of twisting angles on different properties of bilayer graphene need to be comprehensively investigated in order to fully understand its mechanism. In this work, classical molecular dynamics simulations are performed to calculate the interfacial thermal resistance (R) at twisting angles from 0 degrees to 359 degrees. Due to the symmetric structures of the honeycomb lattice, only angles from 0 degrees to 60 degrees are needed but the full spectrum is explored to generate the complete picture of R with theta. It was reported that the interfacial thermal resistance changes periodically with the twisting angle, with the smallest R values at every 60 degrees starting from 0 degrees and the largest values at every 60 degrees starting from 30 degrees. The phonon density of states and radial distribution functions are calculated to explain the predicted results. The effects of temperature and single- and bi-direction tensile strains on the calculated interfacial thermal resistance are also studied. The results in this work contribute to the fundamental understanding of the thermal properties in twisted bilayer graphene and provide reasonable guidelines to its applications in thermal management devices.

Automated summary

It was found that twisting angles have a periodic effect on the interfacial thermal resistance in bilayer graphene, with the smallest values occurring at angles starting from 0 degrees and the largest values occurring at angles starting from 30 degrees. The phonon density of states and radial distribution functions were calculated to explain the results, and the effects of temperature and tensile strains on thermal resistance were also studied.