Quantum mechanical calculation of Rydberg-Rydberg autoionization rates

We present quantum mechanical calculations of Auger decay rates for two Rubidium Rydberg atoms with weakly overlapping electron clouds. We neglect exchange effects and consider tensor products of independent atom states forming an approximate basis of the two-electron state space. We consider large sets of two-atom states with randomly chosen quantum numbers and find that the charge overlap between the two Rydberg electrons allows one to characterise the magnitude of the Auger decay rates. If the electron clouds overlap by more than one percent, the Auger decay rates increase approximately exponentially with the charge overlap. This finding is independent of the energy of the initial state.

Few-Body Bound States of Dipole-Dipole Interacting Rydberg Atoms

We show that the resonant dipole-dipole interaction can give rise to bound states between two and three Rydberg atoms with non-overlapping electron clouds. The dimer and trimer states arise from avoided level crossings between states converging to different fine structure manifolds in the limit of separated atoms. We analyze the angular dependence of the potential wells, characterize the quantum dynamics in these potentials and discuss methods for their production and detection. Typical distances between the atoms are of the order of several micrometers which can be resolved in state-of-the-art experiments. The potential depths and typical oscillation frequencies are about one order of magnitude larger as compared to the dimer and trimer states investigated in [PRA $textbf{86}$ 031401(R) (2012)] and [PRL $textbf{111}$ 233003 (2014)], respectively. We find that the dimer and trimer molecules can be aligned with respect to the axis of a weak electric field.

Three-body bound states in dipole-dipole interacting Rydberg atoms

We show that the dipole-dipole interaction between three identical Rydberg atoms can give rise to bound trimer states. The microscopic origin of these states is fundamentally different from Efimov physics. Two stable trimer configurations exist where the atoms form the vertices of an equilateral triangle in a plane perpendicular to a static electric field. The triangle edge length typically exceeds $Rapprox 2,mutext{m}$, and each configuration is two-fold degenerate due to Kramers degeneracy. The depth of the potential wells and the triangle edge length can be controlled by external parameters. We establish the Borromean nature of the trimer states, analyze the quantum dynamics in the potential wells and describe methods for their production and detection.

Abelian and non-Abelian gauge fields in dipole-dipole interacting Rydberg atoms

We show that the dipole-dipole interaction between two Rydberg atoms can lead to substantial Abelian and non-Abelian gauge fields acting on the relative motion of the two atoms. We demonstrate how the gauge fields can be evaluated by numerical techniques. In the case of adiabatic motion in a single internal state, we show that the gauge fields give rise to a magnetic field that results in a Zeeman splitting of the rotational states. In particular, the ground state of a molecular potential well is given by the first excited rotational state. We find that our system realises a synthetic spin-orbit coupling where the relative atomic motion couples to two internal two-atom states. The associated gauge fields are non-Abelian.