Towards Laser Controlled Generation of Rydberg State, One-Electron Ions

Joan Dreiling, Shannon Fogwell Hoogerheide, Aung Naing +1 more

Joseph N. Tan, Samuel M. Brewer, Nicholas D. Guise

Limei Wang, Markus Deiß, Georg A. Raithel +1 more

Abstract We present a method to control collisions between ultracold neutral atoms in the electronic ground state and trapped ions. During the collision, the neutral atom is resonantly excited by a laser to a low-field-seeking Rydberg state, which is repelled by the ion. As the atom is reflected from the ion, it is de-excited back into its electronic ground level. The efficiency of shielding is analyzed as a function of laser frequency and power, initial atom-ion collision energy, and collision angle. The suitability of several Rydberg levels of Na and Rb for shielding is discussed. Useful applications of shielding include the suppression of unwanted chemical reactions between atoms and ions, a prerequisite for controlled atom-ion interactions.

Pennan Chinnasamy

Aims: The Morgan’s Lab, at Wesleyan University – Connecticut, experimentally probed the dynamics of an atom/molecule using Semi-Classical approach. The experimental setup at Morgan’s Lab is designed to generate a neutral atomic or molecular beam, which is then excited with a finely tuned laser to Rydberg states; the highest quantized energy states the electron can be in before ionization. Study Design: In this current study, the potential of the Penning Ionization Gauge (PIG) as an ion source was evaluated for the Hydrogen atom. Place and Duration of Study: Physics Department, Wesleyan University, Middletown, Connecticut, USA, between June 2007 and August 2009. Methodology: The experimental setup is designed to generate a neutral atomic or molecular beam, which is then excited with a finely tuned laser to Rydberg states; the highest quantized energy states the electron can be in before ionization. The setup consists of an ion beam system consisting of a fast- metastable machine, vacuum pumping systems, an oven, a laser system consisting of a master YAG laser and a slave tunable dye laser, a second harmonic generator for doubling the frequency of the laser beam, Stark plate assembly, an ion detection system and a computer based data acquisition system with LABVIEW software. Results: The PIG found to populate the Hydrogen Rydberg states at 300% times more than the conventional ion source (8 µ Amp Vs. 2 µ Amp). Such high populations of ions lead to a high population of Rydberg states which in turn aided the overall experiment. Conclusion: A better understanding of the dynamics of an electron can aid experiments in condensed matter physics and molecular physics. Obtaining high population of Rydberg states can aid in increasing electron dynamic experiments by increasing the resolution of the scaled-energy absorption spectra. Penning Ionization Gauge (PIG) showed to have a better potential in producing high energy Rydberg states for the hydrogen gas.

David Grimes, Yan Zhou, Timothy Barnum +3 more

Robin Thomm

Trapped ions are one of the leading platforms for quantum technologies due to their excellent control over their internal electronic and external motional degrees of freedom. Many techniques and interesting effects rely on the coupling of the ions to their motion, which makes precise control of them paramount. In this work, two novel techniques for motional state detection are presented. They allow the probing of certain motional states with a single measurement, without affecting the motion of the measured ion. These techniques are employed to generate and detect a highly entangled state between two motional modes in a novel manner. Furthermore, we harness the rich and intricate dynamics arising from the coupling of the ion's motion to its electronic degrees of freedom to study the emergence of interference. Theoretical predictions, describing interference both in the quantum and the classical regimes, are verified, offering a new and more intuitive description of interference, not just for trapped ions, but for a variety of systems that can be described in a similar way. On the other hand, Rydberg excitation with trapped ions enables new interaction mechanisms and makes them extremely sensitive to their surroundings. This thesis presents advances towards Rydberg experiments with longer ion strings and concludes with a first demonstration of coherent population transfer between Rydberg states in trapped ions. The methods developed significantly increase the toolbox for trapped Rydberg ions, enabling more sophisticated experiments, especially when multiple different Rydberg states are involved, and allow more flexibility when using longer ion strings.