Rydberg Atom Interactions

Kashif Ammar Yasir, Wu-Ming Liu

Thomas F. Gallagher

The large size and low binding energies, scaling as n 4 and n −2 , of Rydberg atoms make them nearly irresistible subjects for collision experiments. While one might expect collision cross sections to be enormous, by and large they are not. In fact, Rydberg atoms are quite transparent to most collision partners. Collisions involving Rydberg atoms can be broken into two general categories, collisions in which the collision partner, or perturber, interacts with the Rydberg atom as a whole, and those in which the perturber interacts separately with the ionic core and the Rydberg electron. The difference between these two categories is in essence a question of the range of the interaction between the perturber and the Rydberg atom relative to the size of the Rydberg atom. A few examples serve to clarify this point. A Rydberg atom interacting with a charged particle is a charge–dipole interaction with a 1/ R 2 interaction potential, and the resonant dipole–dipole interaction between two Rydberg atoms has a 1/ R 3 interaction potential. Here R is the internuclear separation of the Rydberg atom and the perturber. In both of these interactions the perturber interacts with the Rydberg atom as a whole. On the other hand when a Rydberg atom interacts with a N 2 molecule the longest range atom–molecule interaction is a dipole–induced dipole interaction with a potential varying as 1/ R 6 .

Raymond Flannery, Valentin N. Ostrovsky, N. V. Prudov +1 more

R. F. Stebbings, F. B. Dunning

List of contributors Preface 1. Rydberg atoms in astrophysics A. Dalgarno 2. Theoretical studies of hydrogen Rydberg atoms in electric fields R. J. Damburg and V. V. Kolosov 3. Rydberg atoms in strong fields D. Kleppner, Michael G. Littman and Myron L. Zimmerman 4. Spectroscopy of one- and two-electron Rydberg atoms C. Fabre and S. Haroche 5. Interaction of Rydberg atoms with blackbody radiation T. F. Gallagher 6. Theoretical approaches to low-energy collisions of Rydberg atoms with atoms and ions A. P. Hickman, R. E. Olson and J. Pascale 7. Experimental studies of the interaction of Rydberg atoms with atomic species at thermal energies F. Gounand and J. Berlande 8. Theoretical studies of collisions of Rydberg atoms with molecules Michio Matsuzawa 9. Experimental studies of thermal-energy collisions of Rydberg atoms with molecules F. B. Dunning and R. F. Stebbings 10. High-Rydberg molecules Robert S. Freund 11. Theory of Rydberg collisions with electrons, ions and neutrals M. R. Flannery 12. Experimental studies of the interactions of Rydberg atoms with charged particles J. -F. Delpech 13. Rydberg studies using fast beams Peter M. Koch Index.

Georg A. Raithel

Brenton Knuffman

In this thesis, we examine the ponderomotive interaction between an applied optical field and a highly excited Rydberg electron. An atom in a Rydberg state is essentially composed of an electron loosely bound, at a relatively large radial separation, to a positive ionic core. As such, the ponderomotive interaction for the Rydberg electron is similar to the interaction with free charges, which has been studied in context of plasma physics, new particle accelerator techniques, ion trapping, and electron diffraction among others. We are focused on using the ponderomotive interaction with the Rydberg electron to exert control over both the center-of-mass and electronic states of translationally cold Rydberg atoms. These capabilities can be adapted as tools for application in many experiments in areas such as atomic spectroscopy and quantum information processing. Our theoretical investigations have provided a well-defined parameter space for our experimental work and have allowed us to develop experimental methods appropriate for studying Rydberg atoms in ponderomotive potentials. In dense gases of cold Rydberg atoms, rich dynamics stem from electric multipole interactions among the Rydberg atoms. For example, interatomic forces between Rydberg atoms cause state-changing collisions which can significantly increase the kinetic energy of the colliding atoms. In addition to the studies of Rydberg atoms in ponderomotive potentials, we discuss collisions of cold Rydberg atoms in which internal energy of the Rydberg atoms is converted into kinetic energy.