Laser-induced electron localization in a triatomic molecular ion

We demonstrate theoretically that by employing an intense few-cycle, circularly polarized laser pulse, two-dimensional localization of the electronic wave function in laser-driven H-3(2+) can be controlled by varying the carrier-envelope phase (CEP). In the reaction H-3(2+) -> H + H+ + H+, it is possible to select which one of the protons the electron finally binds to by tuning the value of the CEP. A complex asymmetry measure is introduced to quantify the degree of asymmetry induced by the laser field. In contrast to previous investigations of electron localization where only diatomic molecules were considered, our results extend CEP control of intramolecular electron motion to triatomic systems. This provides a step toward strong-field spatial and temporal control of electron dynamics in polyatomic molecules.