Population transfer collisions involving nD Rydberg atoms in a CO $_{2}$ optical dipole trapPopulation transfer collisions involving nD Rydberg atoms in a CO$_{2}$ optical dipole trap

Jorge Douglas Massayuki Kondo, Luís F. Gonçalves, Jonathan Tallant +1 more

Bulletin of the American Physical SocietyJun 5, 20140 citations

Electric Field Effects in the Excitation of Cold Rydberg-Atom Pairs

V. A. Nascimento, L. L. Caliri, Arne Schwettmann +2 more

In this work, we study the role of the ac Stark effects on the excitation of nS1/2 cold Rydberg atoms produced in a rubidium magneto-optical trap. We have observed an atomic population in the nP3/2 state after excitation of nS1/2 for 29<or=n<or=37. Such an observation is normally attributed to binary collisions; however, the interaction between Rb nS1/2 atoms is repulsive. To explain our results, the dipole-dipole interaction and ac Stark shifts from the excitation laser must be considered. We find that the Rydberg-atom-pair state asymptotically correlating to nP3/2+(n-1)P3/2 is excited directly.In this work, we study the role of the ac Stark effects on the excitation of nS1/2 cold Rydberg atoms produced in a rubidium magneto-optical trap. We have observed an atomic population in the nP3/2 state after excitation of nS1/2 for 29<or=n<or=37. Such an observation is normally attributed to binary collisions; however, the interaction between Rb nS1/2 atoms is repulsive. To explain our results, the dipole-dipole interaction and ac Stark shifts from the excitation laser must be considered. We find that the Rydberg-atom-pair state asymptotically correlating to nP3/2+(n-1)P3/2 is excited directly.

Physical Review LettersMay 27, 200924 citations

Cold collisions with Rydberg atoms

André Luiz de Oliveira, M. Mancini, Vanderlei Salvador Bagnato +1 more

Jan 1, 20030 citations

Cold Rydberg gas dynamics

Alisa I. Walz‐Flannigan

We have observed the evolution of cold Rydberg gases and ultracold plasmas in an environment that allows for the control of interactions of the blackbody radiation temperature from 4K to 300K. The work in this thesis describes the influence of initial densities, populations, excitation state, evolution time and thermal background temperature on the evolution of cold Rydberg gases as well as directly excited ultracold plasmas. With some initial ionization, cold-Rydberg-atom gases easily develop a positive space charge that traps electrons for times on the order of tens of mus. This acts as a catalyst for electron-Rydberg atom collisions, increasing the collision probabilities by orders of magnitude and profoundly altering the final state of the Rydberg gas. Using state-selective field ionization, we have provided direct proof that these collisions cause changes in l-states, and we have seen the first experimental evidence that they also lead to inelastic n-changing collisions, as predicted by theory. We have also found evidence for Rydberg-Rydberg collisions, enabled by the attractive electric-dipole forces between atoms in high-l states and possibly by van-der-Waal's interactions at very high-n . Thermal interactions are seen to influence the formation of a plasma from a cold Rydberg gas. Plasmas form more easily in the presence of a 300K radiation field than at 4K, due to the contribution of thermal ionization to the plasma formation. The background temperature also appears to affect the electron temperature in both the directly excited plasma and the plasma spontaneously formed from a cold Rydberg gas. In Rydberg atom gases that have undergone partial ionization, electron temperatures were estimated using the dependence of n-changing collisions on the electron temperature.We have observed the evolution of cold Rydberg gases and ultracold plasmas in an environment that allows for the control of interactions of the blackbody radiation temperature from 4K to 300K. The work in this thesis describes the influence of initial densities, populations, excitation state, evolution time and thermal background temperature on the evolution of cold Rydberg gases as well as directly excited ultracold plasmas. With some initial ionization, cold-Rydberg-atom gases easily develop a positive space charge that traps electrons for times on the order of tens of mus. This acts as a catalyst for electron-Rydberg atom collisions, increasing the collision probabilities by orders of magnitude and profoundly altering the final state of the Rydberg gas. Using state-selective field ionization, we have provided direct proof that these collisions cause changes in l-states, and we have seen the first experimental evidence that they also lead to inelastic n-changing collisions, as predicted by theory. We have also found evidence for Rydberg-Rydberg collisions, enabled by the attractive electric-dipole forces between atoms in high-l states and possibly by van-der-Waal's interactions at very high-n . Thermal interactions are seen to influence the formation of a plasma from a cold Rydberg gas. Plasmas form more easily in the presence of a 300K radiation field than at 4K, due to the contribution of thermal ionization to the plasma formation. The background temperature also appears to affect the electron temperature in both the directly excited plasma and the plasma spontaneously formed from a cold Rydberg gas. In Rydberg atom gases that have undergone partial ionization, electron temperatures were estimated using the dependence of n-changing collisions on the electron temperature.

Jan 1, 20041 citation

Interactions of cold Rydberg atoms

Georg A. Raithel

Bulletin of the American Physical SocietyJun 8, 20070 citations

Cold Rydberg atoms in a CO

_{2}

optical dipole trap

Population transfer collisions involving nD Rydberg atoms in a CO

_{2}

optical dipole trap