Xin WU

In two-dimensional (2D) heterosystems, the contribution of coherent phonon transport makes superlattices with high interface density exhibit unexpected high thermal conductivity. Herein, inspired by mathematics, we demonstrate efficient suppression of phonon thermal transport in a 2D heterosystem constituted of graphene and hexagonal boron nitride based on the Golomb ruler sequences. This design realizes extreme suppression of thermal conductivity with a minimal number of interfaces, and without any defects or dopants. Extensive numerical simulations combined with wave packet analysis show that the Golomb ruler sequence largely cancels the coherent phonon transport. This work, as the first attempt for realizing novel thermal physics using the mathematically inspired Golomb ruler design, provides a new and efficient solution for the suppression of thermal transport in 2D heterosystems.

The development of emerging technologies, such as quantum computing and semiconductor electronics, emphasizes the growing significance of thermal management at cryogenic temperatures. Herein, by designing isotope interfaces based on the Golomb ruler, we achieved effective suppression of the phonon thermal transport of cryogenic graphene. The pronounced disordering of the Golomb ruler sequence results in the stronger suppression of thermal transport compared to other sequences with the same isotope doping ratio. We demonstrated that the Golomb ruler-based isotope interfaces have strong scattering and confinement effects on phonon transport via extensive molecular dynamics simulations combined with wave packet analysis, with a proper correction for the missing quantum statistics. This work provides a new stream for the design of thermal transport suppression under cryogenic conditions and is expected to expand to other fields.