Rydberg carbon clusters prepared by pulsed field recombination

The technique of pulsed field recombination is used to recombine a free electron with carbon cation clusters, ranging from C⁺₆₀ to C⁺₅₀. It is shown that after recombination the electron is left in a highly excited state. The recombination method produces a Rydberg state (n ~ 180) in a large carbon cluster, such as C₆₀, with an electronic energy spread of ~ 1 K. We measured a recombination efficiency of ~ 6%.