Peeling graphite layer by layer reveals the charge exchange dynamics of ions inside a solid
Anna Niggas, Sascha Creutzburg, Janine Schwestka, Benjamin Wöckinger, Tushar Gupta, P.L. Grande, Dominik Eder, J. P. Marques, Bernhard C. Bayer, F. Aumayr, Robert Bennett, R. Wilhelm
Abstract
Abstract Over seventy years ago, Niels Bohr described how the charge state of an atomic ion moving through a solid changes dynamically as a result of electron capture and loss processes, eventually resulting in an equilibrium charge state. Although obvious, this process has so far eluded direct experimental observation. By peeling a solid, such as graphite, layer by layer, and studying the transmission of highly charged ions through single-, bi- and trilayer graphene, we can now observe dynamical changes in ion charge states with monolayer precision. In addition we present a first-principles approach based on the virtual photon model for interparticle energy transfer to corroborate our findings. Our model that uses a Gaussian shaped dynamic polarisability rather than a spatial delta function is a major step in providing a self-consistent description for interparticle de-excitation processes at the limit of small separations.