The study investigates the dimensional crossover of thermal transport in few-layer graphene (FLG) materials, focusing on the transition from two-dimensional (2-D) to three-dimensional (3-D) behavior. The researchers found that the room-temperature thermal conductivity of FLG changes from approximately 3000 W/mK to 1500 W/mK as the number of atomic planes increases from 2 to 4. This crossover is explained by the cross-plane coupling of low-energy phonons and changes in phonon Umklapp scattering. The results highlight the importance of intrinsic mechanisms in heat conduction and provide insights into the thermal management of nanoelectronics using FLG. The study also discusses the theoretical basis for the observed phenomena, including the divergence of thermal conductivity in 2-D and 1-D systems, and the role of Umklapp scattering in different crystal structures.The study investigates the dimensional crossover of thermal transport in few-layer graphene (FLG) materials, focusing on the transition from two-dimensional (2-D) to three-dimensional (3-D) behavior. The researchers found that the room-temperature thermal conductivity of FLG changes from approximately 3000 W/mK to 1500 W/mK as the number of atomic planes increases from 2 to 4. This crossover is explained by the cross-plane coupling of low-energy phonons and changes in phonon Umklapp scattering. The results highlight the importance of intrinsic mechanisms in heat conduction and provide insights into the thermal management of nanoelectronics using FLG. The study also discusses the theoretical basis for the observed phenomena, including the divergence of thermal conductivity in 2-D and 1-D systems, and the role of Umklapp scattering in different crystal structures.