Revisiting phonon-phonon scattering in single-layer graphene

Abstract

Understanding the mechanisms of thermal conduction in graphene is a long-lasting research topic, due to its high thermal conductivity. Peierls-Boltzmann transport equation (PBTE) based studies have revealed many unique phonon transport properties in graphene, but most previous works only considered three-phonon scatterings and relied on interatomic force constants (IFCs) extracted at 0 K. In this paper, we explore the roles of four-phonon scatterings and the temperature dependent IFCs on phonon transport in graphene through our PBTE calculations. We demonstrate that the strength of four-phonon scatterings would be severely overestimated by using the IFCs extracted at 0 K compared with those corresponding to a finite temperature, and four-phonon scatterings are found to significantly reduce the thermal conductivity of graphene even at room temperature. In order to reproduce the prediction from molecular dynamics simulations, phonon frequency broadening has to be taken into account when determining the phonon scattering rates.Our study elucidates the phonon transport properties of graphene at finite temperatures, and could be extended to other crystalline materials.

A minimal Tersoff potential for diamond silicon with improved descriptions of elastic and phonon transport properties

“…To explore the influence of quantum effects, we calculate the thermal conductivity by iteratively solving the Peierls-Boltzmann transport equation (PBTE). In our calculations, we consider both three-phonon and fourphonon scatterings [57] and temperature-dependent interatomic force constants [58]. In this method, both classical and quantum statistics for the phonon population can be conveniently considered.…”

“…For details, see Ref. [57]. Figure 6 shows the classical and quantum thermal conductivity from the PBTE calculations using the minimal Tersoff potential, compared to the MD and experimental data.…”

Unification of nonequilibrium molecular dynamics and the mode-resolved phonon Boltzmann equation for thermal transport simulations

“…A quantitative comparison of NEMD and phonon BTE is performed in this study using silicon as the testing material. However, there are several key differences between this comparison and those that were done previously [19,[34][35][36]. First, the input parameters of phonon BTE (phonon specific heat, group velocity, and relaxation time) are extracted from the same interatomic potential as those used in NEMD.…”

“…pacity of the mode (q, s) are simply calculated by v(q, s) = ∂ω(q, s)/∂q and c(q, s) = ∂hω(q, s)n 0 (q, s)/∂T with the phonon population function being n 0 (q, s). In order to make a fair comparison of the NEMD and phonon BTE results, the phonon population function used in this work has the same form as the standard Bose-Einstein distribution, n 0 (q, s) = 1/(exp(hω(q, s)/k B T ) − 1), but with a modified Planck's constant, which is 1/100 of the original value[34]. This treatment could reproduce the classical distribution in MD 155308-Comparisons of temperature profiles and heat flux profiles between the NEMD simulations with the Langevin thermostat and the BTE calculations with the thermalizing boundary condition for two different sample lengths of (a) 13.0 nm and (b) 56.0 nm.…”

Monitoring anharmonic phonon transport across interfaces in one-dimensional lattice chains

“…While in the FPU-β lattices the anharmonicity comes from the quartic terms in the potential V, for realistic materials the anharmonicity to all orders occurs and affects the phonon spectra under finite temperatures. Although a few approaches have been proposed to treat phonon renormalization in bulk materials [38][39][40], these attempts cannot be applied to interfacial systems directly due to the breakdown of the translational invariance. It is worth mentioning that the current method does not have such a limitation and can be used in complex interfacial systems, as the renormalization effects are intrinsically considered in the molecular dynamics simulations.…”