Related papers: Back and forth transfer and coherent coupling in a…
Resonant energy transfers, i.e. the non-radiative redistribution of an electronic excitation between two particles coupled by the dipole-dipole interaction, lie at the heart of a variety of chemical and biological phenomena, most notably…
In this thesis are presented analytical results and numerical simulations concerning resonant processes in a frozen gas. This work was begun with the intent of modeling experiments involving energy transfer due to dipole-dipole interactions…
Cold Rydberg atoms subject to long-range dipole-dipole interactions represent a particularly interesting system for exploring few-body interactions and probing the transition from 2-body physics to the many-body regime. In this work we…
We have observed resonant energy transfer between cold Rydberg atoms in spatially separated cylinders. Resonant dipole-dipole coupling excites the 49s atoms in one cylinder to the 49p state while the 41d atoms in the second cylinder are…
Using time-resolved measurements, we demonstrate coherent collective Rydberg excitation crossing over into Rydberg blockade in a dense and ultracold gas trapped at a distance of 100 $\mu$m from a room-temperature atom chip. We perform…
We show that nuclear motion of Rydberg atoms can be induced by resonant dipole-dipole interactions that trigger the energy transfer between two energetically close Rydberg states. How and if the atoms move depends on their initial…
We investigate the transport of excitations through a chain of atoms with non-local dissipation introduced through coupling to additional short-lived states. The system is described by an effective spin-1/2 model where the ratio of the…
We study coherent excitation hopping in a spin chain realized using highly excited individually addressable Rydberg atoms. The dynamics are fully described in terms of an XY spin Hamiltonian with a long range resonant dipole-dipole coupling…
We demonstrate a non-equilibrium phase transition in a dilute thermal atomic gas. The phase transition, between states of low and high Rydberg occupancy, is induced by resonant dipole-dipole interactions between Rydberg atoms. The gas can…
Cold atomic gases resonantly excited to Rydberg states can exhibit strong optical nonlinearity at the single photon level. We observe that in such samples radiation trapping leads to an additional mechanism for Rydberg excitation.…
We probe resonant dipolar interactions between ultracold $^{40}$K$^{87}$Rb molecules and Rydberg $^{87}$Rb atoms in an optically trapped ensemble. Through state-selective ionization detection of the KRb molecules, we observe resonant energy…
High resolution laser excitation of np Rydberg states of cesium atoms shows a dipole blockade at F\"{o}rster resonances corresponding to the resonant dipole-dipole energy transfer of the np + np → ns + (n + 1)s reaction. The…
Pulsed laser excitation of a dense ultracold Cs vapor has been used to study the pairwise interactions between Cs atoms excited to $n$p$_{3/2}$ Rydberg states of principal quantum numbers in the range $n=22-36$. Molecular resonances were…
Rydberg-atom ensembles are switched from a weakly- into a strongly-interacting regime via adiabatic transformation of the atoms from an approximately non-polar into a highly dipolar quantum state. The resultant electric dipole-dipole forces…
The dipole-dipole interaction among ultra-cold Rydberg atoms is simulated. We examine a general interaction scheme in which two atoms excited to the x and x' states are converted to y and y' states via a Forster resonance. The atoms are…
We report the creation of an interacting cold Rydberg gas of strontium atoms. We show that the excitation spectrum of the inner valence electron is sensitive to the interactions in the Rydberg gas, even though they are mediated by the outer…
We describe a new mechanism of decoherence in excited atoms as a result of thermal particles scattering by the atomic nucleus. It is based on the idea that a single scattering will produce a sudden displacement of the nucleus, which will be…
Ultracold Rydberg atom arrays are an emerging platform for quantum simulation and computing. However, decoherence in these systems remains incompletely understood. Recent experiments [Guardado-Sanchez et al. Phys. Rev. X 8, 021069 (2018)]…
We present experimental results on the controlled de-excitation of Rydberg states in a cold gas of Rb atoms. The effect of the van der Waals interactions between the Rydberg atoms is clearly seen in the de-excitation spectrum and dynamics.…
We observe the direct excitation of pairs of Cs atoms from the ground state to molecular states correlating asymptotically to $ns\,n'f$ asymptotes. The molecular resonances are interpreted as originating from the dipole-quadrupole…