Using the carrier-envelope phase to control strong-field dissociation of HeH+ at midinfrared wavelengths

Abstract

We study the response of ${\mathrm{HeH}}^{+}$ to an intense, few-cycle laser pulse. Specifically, we present the carrier-envelope phase (CEP) dependence of the kinetic-energy-release spectrum, the spatial asymmetry, and the total dissociation probability in two-cycle pulses with an intensity of ${10}^{14}\phantom{\rule{0.28em}{0ex}}{\mathrm{W}/\mathrm{cm}}^{2}$ and wavelengths of 3200 and 4000 nm. Strong spatial asymmetries are found in spite of the fact that the electron always becomes localized as He+${\mathrm{H}}^{+}$, demonstrating that control of such asymmetries can be obtained via control of the nuclear degrees of freedom---as opposed to its usual interpretation as control over the electronic degrees of freedom. We explain these CEP effects in terms of our photon-phase representation.