Electron correlation in channel-resolved strong-field molecular double ionization

Abstract

Strong-field ionization plays a fundamental role in attosecond science as the source of electron wave packets which ultimately provide attosecond bursts of radiation as they are driven back to the atom or molecule of origin. Double ionization is an important probe of electron correlation (correlated electron dynamics), which lies at the core of attosecond science. While double ionization of atoms has been studied extensively, the double ionization of molecules is relatively unexplored---particularly for the case of polyatomic systems. We present coincidence (three and four particle) velocity map imaging measurements of molecular double ionization in 1,3-cyclohexadiene and 1,4-cyclohexadiene using few cycle ($\ensuremath{\sim}10$ fs) laser pulses. Our measurements allow us to distinguish between dissociative and nondissociative double ionization, and we find a difference in the correlation of electrons that come from the different channels.