Anomalous temperature-dependent heat transport in one-dimensional momentum-conserving systems with soft-type interparticle interaction

TL;DR

This study numerically explores heat transport in a one-dimensional lattice with soft-type anharmonic interactions, revealing anomalous temperature-dependent behavior similar to hard-type systems despite phonon softening.

Contribution

It demonstrates that soft-type anharmonicity leads to anomalous heat transport with temperature-dependent scaling, expanding understanding of nonlinear phonon dynamics.

Findings

Heat transport remains anomalous at various temperatures.

Soft-type anharmonicity does not fully damp long-wavelength phonons.

Temperature influences the scaling properties of heat transport.

Abstract

We here numerically investigate the heat transport behavior in a one-dimensional lattice with a soft-type (ST) anharmonic interparticle interaction. It is found that with the increase of system's temperature, while the introduction of ST anharmonicity softens phonons and decreases their velocities, this type of nonlinearity like its counterpart of hard type (HT), can still not be able to fully damp the longest wave phonons. Therefore, an anomalous temperature dependent heat transport with certain scaling properties similarly to those in the Fermi-Pasta-Ulam like systems with HT interactions can be seen. Our detailed examination from simulations well verify this temperature dependent behavior.