Interaction Enhanced Imaging of Rydberg P states

Abstract

The Interaction Enhanced Imaging technique allows to detect the spatial distribution of strongly interacting impurities embedded within a gas of background atoms used as a contrast medium [1]. Here we present a detailed study of this technique, applied to detect Rydberg P states. We experimentally realize fast and efficient three-photon excitation of P states, optimized according to the results of a theoretical effective two-level model. Few Rydberg P -state atoms, prepared in a small cloud with dimensions comparable to the blockade radius, are detected with a good sensitivity by averaging over 50 shots. The main aspects of the technique are described with a hard-sphere model, finding good agreement with experimental data. This work paves the way to a non-destructive optical detection of single Rydberg atoms with high spatial and temporal resolution.

Density matrix reconstruction of three-level atoms via Rydberg electromagnetically induced transparency

“…This beam is focused into the center of the cloud with a waist of approximately 15 µm and an intensity of approximately 0.9 kW/cm 2 . The coupling and probing lasers are both frequency stabilized via the Pound-Drever-Hall method to a high finesse and ultra-stable passive Fabry-Pérot cavity [36,44] to a linewidth of ∼ 10 kHz which is much smaller than the Rydberg-state dephasing rate observed in our experiments.…”

“…The combination of optical and population-based probing of coherently driven three-level atomic systems as realised in these experiments offers new avenues for studying multilevel interference effects such as electromagnetically-inducedtransparency, coherent population trapping and stimulated-Raman adiabatic passage with simultaneous access to all degrees of freedom. Furthermore, the reconstructed spatially-dependent Rabi frequency, Rydberg population and optical susceptibility serve as valuable input for modeling light propagation in interacting Rydberg ensembles [42,47,48,49] and realizing new non-destructive imaging techniques for strongly-interacting particles, with single atom sensitivity [34,35,36,50]. Ultimately, these efforts complemented by the technique described here, will enable new studies of the correlations between atoms and photons induced by Rydberg-Rydberg interactions, relevant for example to current and future studies of nonlinear light propagation in strongly interacting media [20,51,52,53,54] and Rydberg dressed quantum fluids [55,56,57] which exploit strong-atom light coupling in three-level atomic systems.…”

“…Through time resolved measurements of the transparency signal it has been shown that it is possible to reconstruct the Rydberg population [32,33]. Additionally, all-optical techniques which exploit the strong interactions between Rydberg "impurity" states and dark-state polaritons enable position and time-resolved measurements of the Rydberg impurity density [34,35,36].…”

Depletion imaging of Rydberg atoms in cold atomic gases

“…The latter has been explored by means of tomographic techniques based on field-ionization of the Rydberg states and ion counting on an MCP detector [17] and by locally resolving the autoionization of a Rydberg cloud [18] or of an ultracold plasma of Rydberg atoms [19]. Another approach, called interaction enhanced imaging [20][21][22], reveals the presence of down to a few Rydberg excitations by using the surrounding ground state atoms under electromagnetically induced transparency coupling as a contrast medium. In the non-interacting regime, it has been possible to reconstruct the three-dimensional Rydberg distribution and even the density matrix from joint measurements of the local optical spectrum and of the excited atom number [23].…”