Fig. 5.

Calculated strain and resistivity, together with a schematic for the importance of time scales of rippling. (A) Schematic representation of the ultrafast attenuation (5 ps) of the intrinsic ripples due to the excitation of nonthermal in-plane acoustic phonons (LA and TA), followed by a recovery, or even enhancement, of the rippling structure in 50 ps, as caused by the increased population of out-of-plane phonon modes (ZA). (B) The effect of the in-plane strain on the electrical resistivity of graphene at different initial temperatures, as derived from the theory given in ref. 50, is depicted for strain values experimentally measured here. The blue line represents the contribution from in-plane phonons, whereas the gray lines represent the contribution from ZA phonons at three different strains. (C) Conceptual drawing of an ultrafast optical switch based on graphene.