Triggering waves in nonlinear lattices: Quest for anharmonic phonons and corresponding mean free paths

Abstract

Guided by a stylized experiment we develop a self-consistent anharmonic phonon concept for nonlinear lattices which allows for explicit "visualization." The idea uses a small external driving force which excites the front particles in a nonlinear lattice slab and subsequently one monitors the excited wave evolution using molecular dynamics simulations. This allows for a simultaneous, direct determination of the existence of the phonon mean free path with its corresponding anharmonic phonon wavenumber as a function of temperature. The concept for the mean free path is very distinct from known prior approaches: the latter evaluate the mean free path only indirectly, via using both, a scale for the phonon relaxation time and yet another one for the phonon velocity. Notably, the concept here is neither limited to small lattice nonlinearities nor to small frequencies. The scheme is tested for three strongly nonlinear lattices of timely current interest which either exhibit normal or anomalous heat transport.

References in corpus (5)

• Heat Transport in low-dimensional systems
• Anomalous Heat Conduction and Anomalous Diffusion in Low Dimensional Nanoscale Systems
• Phonon Quasi-Particles and Anharmonic Free Energy in Complex Systems
• Anomalous energy transport in the FPU-beta chain
• Effective phonons in anharmonic lattices: anomalous vs normal heat conduction

Cited by in corpus (14)

• Anharmonic Phonon Quasiparticle Theory of Zero-point and Thermal Shifts in Insulators: Heat Capacity, Bulk Modulus, and Thermal Expansion
• 1D momentum-conserving systems: the conundrum of anomalous versus normal heat transport
• Role of the range of the interactions in thermal conduction
• Renormalized phonons in nonlinear lattices: A variational approach
• Interfacial thermal transport with strong system-bath coupling: A phonon delocalization effect
• Examining normal modes as fundamental heat carriers in amorphous solids: the case of amorphous silicon
• Nonequilibrium phonon mean free paths in anharmonic chains
• Temperature dependence of thermal conductivities of coupled rotator lattice and the momentum diffusion in standard map
• Heat conduction and energy diffusion in momentum-conserving 1D full lattice ding-a-ling model
• Solitons as candidates for energy carriers in Fermi-Pasta-Ulam lattices
• Analytical results for a minimalist thermal diode
• Variational approach to renormalized phonon in momentum-nonconserving nonlinear lattices
• Projective-truncation-approximation study of the one-dimensional ${\varphi }^4$ lattice model
• Approaching the perfect diode limit through a nonlinear interface