Thermal conductance of suspended nanoribbons: interplay between strain and interatomic potential nonlinearity

R.BARRETO; M.F. CARUSELA; MONASTRA A.

JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT

IOP PUBLISHING LTD

Lugar: Londres; Año: 2017 p. 103201 - 103225

1742-5468

We investigate the role that nonlinearity in the interatomic potential has on the thermal conductance of a suspended nanoribbon when it is subjected to a longitudinal strain. To focus on the first cubic and quartic nonlinear terms of a general potential, we propose an atomic system based on an $alpha$-$eta$ Fermi-Pasta-Ulam nearest neighbor interaction.We perform classical molecular dynamics simulations to investigate the contribution of longitudinal, transversal and flexural modes to the thermal conductance as a function of the $alpha$-$eta$ parameters and the applied strain.  We compare the cases where atoms are allowed to vibrate only {it in} plane (2D) with the case of vibrations {it in} and {it out} of plane (3D). We find that the dependence of conductance on $alpha$ and $eta$ relies on a crossover phenomenon between linear/nonlinear delocalized/localized flexural and transversal modes, driven by an on/off switch of the strain.