The Lack of Electron Momentum Correlation in Strong-Field Triple Ionisation of Molecules

We report the results of direct measurements of electron momentum correlation in strong-field-driven molecular triple ionisation. With a camera-based imaging apparatus, measurement of quadruple coincidence (electron-electron-electron-ion) from non-dissociative triple ionisation of benzene and quintuple coincidence (electron-electron-electron-ion-ion) from dissociative triple ionisation of methyl iodide were carried out for the first time. We observed no evidence of momentum correlation among three ejected electrons, which suggests that a sequential triple ionisation process dominates under the employed experimental conditions.