Frustrated tunnelling ionization during strong-field fragmentation of D₃⁺

Abstract

We reveal surprisingly high kinetic energy release in the intense-field fragmentation of D _3 ^+ to D ^+ + D ^+ + D with 10 ^16 W cm ^−2 , 790 nm, 40 fs (and 7 fs) laser pulses. This feature strongly mimics the behaviour of the D ^+ + D ^+ + D ^+ channel. From the experimental evidence, we conclude that the origin of the feature is due to frustrated tunnelling ionization, the first observation of this mechanism in a polyatomic system. Furthermore, we unravel evidence of frustrated tunnelling ionization in dissociation, both two-body breakup to D + D _2 ^+ and D ^+ + D _2 , and three-body breakup to D ^+ + D + D.