Semiclassical Dynamics of Rydberg Electron in a Ponderomotive Optical Lattice

While semiclassical limits of quantum mechanical systems are well-defined in systems with a classically regular counterpart, the quantum behavior of classically chaotic systems remains a topic of investigation. In the past decades, manifestations of chaotic behavior have been demonstrated in model Hamiltonians like dynamical billiards, as well as in physical systems such as the quantum kicked rotor, the diamagnetic hydrogen atom, and Rydberg atoms in strong fields. Here, we numerically investigate the onset of chaos in the semiclassical dynamics of a Rydberg electron subjected to a strong sinusoidal trapping potential implemented via a one-dimensional, GHz-deep ponderomotive optical lattice. In this poster, we will introduce the physical system of interest and present numerical results on classical phase-space dynamics. The system is characterized by electronic energy, z-angular momentum, lattice period and lattice depth. For sufficiently deep lattices, and for appropriate Rydberg states and aspect ratios of atom size to lattice period, the time evolution under the nonlinear optical-lattice potential is found to give rise to ergodicity and exponential divergence of neighboring trajectories. The significance of the results in the corresponding quantum problem will be discussed.