Electronic excitation in an Ar7+ ion traversing a graphene sheet: Molecular dynamics simulations

We studied the interaction between an Ar7+ ion and a graphene sheet by combining real-time propagation of electron wave functions with molecular dynamics simulations. Our calculation supports the fluorescence from Ar7+ ions penetrating the carbon foil [S. Bashkin , Phys. Rev. A 25, 417 (1982)], and it suggests that this fluorescence also occurs even when the thickness of the target is only the monatomic layer and when the incident kinetic energy corresponds to 500 keV. Monitoring the fluorescence is a useful way to detect graphene sheets even with monatomic thickness.