Non-Fourier heat transport in graphene nanoribbons: Regulation of temperature oscillations and cooling effects

Existing research indicates that phonon heat transport in low-dimensional materials exhibits significant non-Fourier heat transport behavior, particularly under ultrafast and nanoscale conditions. This study develops a non-Fourier heat conduction model based on the continuous medium assumption, incorporating both temperature gradient and heat flux hysteresis effects. Using a first-principles finite element numerical simulation framework, we investigate phonon heat transport in graphene nanoribbons under Gaussian transient thermal pulse excitation. Numerical results show that at a low temperature of 80 K, N scattering mechanisms dominate, leading to a temperature oscillation phenomenon characterized by a transition from ballistic to hydrodynamic transport. As the initial temperature increases to 150 and 300 K, R scattering effects become predominant, resulting in a gradual transition of heat transport toward a diffusion mechanism, which significantly diminishes or even eliminates the temperature oscillations. Furthermore, by adjusting the discrete parameters of the Gaussian thermal pulse, localized temperature fluctuations and cooling effects can be induced at 100 K. This research not only provides theoretical support for the quantitative analysis of the microscopic mechanisms of phonon heat transport in low-dimensional materials but also offers potential theoretical foundations for efficient thermal management design in transient thermal grating experiments and graphene-based semiconductor devices.