Long-lived discrete breathers in free-standing graphene

Intrinsic localized modes or discrete breathers (DBs) are investigated by molecular dynamics simulations in free-standing graphene. DBs are generated either through thermal quenching of the graphene lattice or by proper initialization, with frequencies and lifetimes sensitively depending on the interatomic potential describing the carbon-carbon interaction. In the most realistic scenario, for which temperature-dependent molecular dynamics simulations in three dimensions using a graphene-specific interatomic potential are performed, the DBs lifetimes increase to hundreds of picoseconds even at relatively high temperatures. These lifetimes are much higher than those anticipated from earlier calculations, and may enable direct breather observation in Raman spectroscopy experiments. Our simulations provide clear estimation for the temperatures in which DBs are expected to be thermally excited (1500–2000 K) representing a step forward for understanding the nonlinear physics of graphene and designing experiments in order to detect DBs, with possible impact in graphene-based future technological applications.