Quantum-State-Sensitive Detection of Alkali Dimers on Helium Nanodroplets by Laser-Induced Coulomb Explosion

Abstract

Rubidium dimers residing on the surface of He nanodroplets are doubly ionized by an intense fs laser pulse leading to fragmentation into a pair of $\mathrm{R}{\mathrm{b}}^{+}$ ions. We show that the kinetic energy of the $\mathrm{R}{\mathrm{b}}^{+}$ fragment ions can be used to identify dimers formed in either the X ${}^1{\Sigma }_{\mathrm{g}}^{+}$ ground state or in the lowest-lying triplet state, a ${}^3{\Sigma }_{\mathrm{u}}^{+}$. From the experiment, we estimate the abundance ratio of dimers in the a and X states as a function of the mean droplet size and find values between 4:1 and 5:1. Our technique applies generally to dimers and trimers of alkali atoms, here also demonstrated for $\mathrm{L}{\mathrm{i}}_2$, $\mathrm{N}{\mathrm{a}}_2$, and ${\mathrm{K}}_2$, and will enable fs time-resolved measurements of their rotational and vibrational dynamics, possibly with atomic structural resolution.

5 pages, 4 figures

References in corpus (5)

• Calculations of static dipole polarizabilities of alkali dimers. Prospects for alignment of ultracold molecules
• Photoionizaton of Pure and Doped Helium Nanodroplets
• Control and femtosecond time-resolved imaging of torsion in a chiral molecule
• Wave packet dynamics of potassium dimers attached to helium nanodroplets
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Cited by in corpus (4)

• Laser-induced Coulomb Explosion Imaging of Alkali Dimers on Helium Nanodroplets
• Nonadiabatic Laser-Induced Alignment Dynamics of Molecules on a Surface
• Time-resolved Coulomb explosion imaging of vibrational wave packets in alkali dimers on helium nanodroplets
• Magnetic deflection of high-spin sodium dimers formed on helium nanodroplets