Photoionization of Rydberg Atoms in Optical Lattices

TL;DR

This paper develops a formalism to analyze photoionization and potential energy curves of Rydberg atoms in optical lattices, revealing how lattice depth influences ionization behavior and atomic lifetimes for quantum control and spectroscopy.

Contribution

It introduces a new formalism for understanding photoionization and potential energy curves of Rydberg atoms in optical lattices across different lattice depths.

Findings

PI effects vary with lattice depth, from negligible to dominant.

Lattice-induced $ ext{l}$-mixing creates complex PEC structures in GHz-deep lattices.

PI cross sections depend strongly on angular momentum and lattice-induced mixing.

Abstract

We develop a formalism for photoionization (PI) and potential energy curves (PECs) of Rydberg atoms in ponderomotive optical lattices and apply it to examples covering several regimes of the optical-lattice depth. The effect of lattice-induced PI on Rydberg-atom lifetime ranges from noticeable to highly dominant when compared with natural decay. The PI behavior is governed by the generally rapid decrease of the PI cross sections as a function of angular-momentum ($\ell$), and by lattice-induced $\ell$-mixing across the optical-lattice PECs. In GHz-deep lattices, $\ell$-mixing leads to a rich PEC structure, and the significant low-$\ell$ PI cross sections are distributed over many lattice-mixed Rydberg states. In lattices less than several tens-of-MHz deep, atoms on low-$\ell$ PECs are essentially $\ell$-mixing-free and maintain large PI cross sections, while atoms on high-$\ell$ PECs trend towards being PI-free. Characterization of PI in GHz-deep Rydberg-atom lattices may be beneficial for optical control and quantum-state manipulation of Rydberg atoms, while data on PI in shallower lattices are potentially useful in high-precision spectroscopy and quantum-computing applications of lattice-confined Rydberg atoms.