Extending the time scale in molecular dynamics simulations: Propagation of ripples in graphene
Vinod K. Tewary
Limited time scale is a major unsolved problem in molecular dynamics (MD) which is the most important tool for modeling time dependent processes in almost all branches of science, especially in the modern field of nanomaterials. Convergence requirement of the numerical integration of the MD nist-equation limits the time step to a few femtoseconds. Hence it requires 106 109 time steps to model many physical processes of practical interest in nanomaterials that occur at time scales of nano to micro seconds. It is a formidable task even for modern computers. Here we show that the time scales can be accelerated by several orders of magnitude by incorporating causal Greens functions in MD. For illustration, we apply the technique to model the propagation of ripples in graphene. Our technique should be applicable to not just the nanomaterials but other physical, chemical, and biological systems where MD is used.