Atomic Rydberg-state excitation in strong spatially inhomogeneous fields

We investigated the Rydberg-state excitation process of a hydrogen atom subjected to spatially homogeneous and inhomogeneous laser fields by means of ab initio calculations. It is found that, comparing with atoms exposed to spatially homogeneous laser fields, the excitation probability decreases and the electron tends to occupy the states with lower principal quantum numbers and angular quantum numbers for atoms in spatially inhomogeneous laser pulses. Furthermore, calculations of a quantum model without taking into account ionization of the electron after it is coherently captured by the Rydberg state are inconsistent with the above-stated findings by ab initio calculations. Analysis indicates that the aforementioned intriguing features can be attributed to the enhanced ionization of the Rydberg states by inhomogeneous laser fields since the distributions of Rydberg states of high principal quantum numbers and angular quantum numbers locate far away from the core where the inhomogeneous electric fields become significant.

Automated summary

This study investigates the excitation process of a hydrogen atom in Rydberg states under spatially homogeneous and inhomogeneous laser fields using ab initio calculations. The results show that, compared with atoms exposed to homogeneous fields, the excitation probability decreases in spatially inhomogeneous laser pulses, and the electron tends to occupy states with lower quantum numbers. Additionally, calculations based on a quantum model that neglects ionization after coherent capture by the Rydberg state are inconsistent with the findings from the ab initio calculations. Analysis suggests that the enhanced ionization of Rydberg states by inhomogeneous laser fields is responsible for these intriguing features, as the distributions of high quantum number Rydberg states are located far from the core where the inhomogeneous electric fields are significant.