Two-Pulse Atomic Coherent Control (2PACC) Spectroscopy of Eley-Rideal Reactions. An Application of an Atom Laser

A spectroscopic application of the atom laser is suggested. The spectroscopy termed 2PACC employs the coherent properties of matter-waves from a two pulse atom laser. These waves are employed to control a gas-surface chemical recombination reaction. The method is demonstrated for an Eley-Rideal reaction of a hydrogen or alkali atom-laser pulse where the surface target is an adsorbed hydrogen atom. The reaction yields either a hydrogen or alkali hydride molecule. The desorbed gas phase molecular yield and its internal state is shown to be controlled by the time and phase delay between two atom-laser pulses. The calculation is based on solving the time-dependent Schrodinger equation in a diabatic framework. The probability of desorption which is the predicted 2PACC signal has been calculated as a function of the pulse parameters.Comment: 29 pages and 11 figure

Collective enhancement and suppression in Bose-Einstein condensates

The coherent and collective nature of Bose-Einstein condensate can enhance or suppress physical processes. Bosonic stimulation enhances scattering in already occupied states which leads to atom amplification, and the suppression of dissipation leads to superfluidity. In this paper, we review several experiments where suppression and enhancement have been observed and discuss the common roots of and differences between these phenomena.Comment: ICAP proceedings; 12 figure

Rethinking “Damage-Centered” Research and Individual Solutions: Cultural Humility as a Framework to Increase Student Diversity in Undergraduate STEM Departments

This study examines data from a participatory research action study on the experiences of underrepresented students in Science, Technology, Engineering, and Mathematics (STEM) fields at a small liberal arts college in the United States. Our analysis aims to move away from the framework that students needed to be taught how to cope with and overcome the challenges they faced in their STEM experiences, including racism and sexism. Instead, we propose a stronger focus on how to end racist, sexist, and other forms of discrimination. We draw on the concept of “cultural humility” as a concrete framework that professors, departments, and institutions can use to approach their work of changing practices, policies, and systems. Results discuss specific strategies that educators and institutions can use to promote a cultural humility framework as one way to create anti-oppressive and equitable classrooms, departments, and institutions

Effects of relative phase and interactions on atom-laser outcoupling from a double-well Bose-Einstein condensate: Markovian and non-Markovian dynamics

We investigate aspects of the dynamics of a continuous atom-laser scheme based on the merging of independently formed atomic condensates. Our theoretical analysis covers the Markovian as well as the non-Markovian operational regimes, and is based on a semiclassical (mean-field) two-mode model. The role of the relative phase between the two condensates and the effect of interatomic interactions on the evolution of the trapped populations and the distribution of outcoupled atoms are discussed.Comment: to appear in J. Phys.

A slow and dark atomic beam

We demonstrate a method to produce a very slow atomic beam from a vapour cell magneto-optical trap. Atoms are extracted from the trap using the radiation pressure imbalance caused by a push beam. An additional transfer beam placed near the center of the trap transfers the atomic beam into an off-resonant state. The velocity of the atomic beam has been varied by changing the intensity of the push beam or the position of the transfer beam. The method can be used to generate a continuous, magnetically guided atomic beam in a dark state.Comment: 14 page