Bulletin of the American Physical Society
42nd Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 56, Number 5
Monday–Friday, June 13–17, 2011; Atlanta, Georgia
Session B6: Undergraduate Session |
Hide Abstracts |
Chair: Katharina Gillen, California Polytechnic State University Room: A706 |
Tuesday, June 14, 2011 10:30AM - 11:00AM |
B6.00001: What's So Interesting About AMO Physics? Invited Speaker: In recent years, DAMOP has expanded to the point where the meeting can be quite daunting for a first-time attendee. This talk will provide an introduction to some of the most exciting current areas of research in Atomic, Molecular, and Optical physics, intended to help undergraduates, beginning graduate students, or physicists from other fields attending their first DAMOP meeting orient themselves. I will introduce the terminology and important experimental and theoretical issues in subfields including (but not limited to) ultra-cold atoms, quantum information, precision measurement, ultra-fast lasers, and atomic and molecular structure and spectroscopy. I will also suggest examples of particularly interesting sessions and presentations at this year's DAMOP. [Preview Abstract] |
Tuesday, June 14, 2011 11:00AM - 11:18AM |
B6.00002: Possibility of Stark-insensitive cotrapping of two atomic species in optical lattices Muir Morrison, V.A. Dzuba, A. Derevianko Much effort has been devoted to removing differential Stark shifts for atoms trapped in specially tailored ``magic" optical lattices, but thus far work has focused on a single trapped atomic species. In this work, we extend these ideas to include two atomic species sharing the same optical lattice. We show qualitatively that, in particular, scalar $J=0$ divalent atoms paired with non-scalar state atoms have the necessary characteristics to achieve such Stark shift cancellation. We then present numerical results on ``magic" trapping conditions for $^{27}$Al paired with $^{87}$Sr, as well as several other divalent atoms. [Preview Abstract] |
Tuesday, June 14, 2011 11:18AM - 11:36AM |
B6.00003: Pair creation rates for one-dimensional fermionic and bosonic vacua Matthew Ware, Q. Su, R. Grobe We compare the creation rates for particle-antiparticle pairs produced by a supercritical force field for fermionic and bosonic model systems. The rates obtained from the Dirac and Klein-Gordon equations can be computed directly from the quantum mechanical transmission coefficients describing the scattering of an incoming particle with the supercritical potential barrier. We provide a unified framework that shows that the bosonic rates can exceed the fermionic ones, as one could expect from the Pauli exclusion principle for the fermion system. The predicted pair-creation rates also match the slopes of the time-dependent particle probabilities obtained from large-scale ab initio numerical simulations based on quantum field theory. [Preview Abstract] |
Tuesday, June 14, 2011 11:36AM - 11:54AM |
B6.00004: Measured Impact of core electrons on Van der Waals potentials Catherine Klauss, Vincent P.A. Lonij, William F. Holmgren, Ivan Hromada, Alex D. Cronin We measured atom-surface Van der Waals potentials ($C_{3}$ coefficients) for Li, Na, K, and Rb atoms by studying diffraction from a nanograting. By focusing on ratios of $C_{3}$, we eliminate systematic errors due to the geometry and roughness of the nanograting. We measured the ratio $C_{3}^{K} / C_{3}^{Na} = 1.544 \pm 0.025$ meVnm$^{3}$. With this $2\%$ precision, our measurements reveal the contribution of core-electrons to atom-surface interactions. We also show that the permittivity $\epsilon(\omega)$ of the surface does not significantly affect the ratios of $C_{3}$. Therefore our results serve as a good test of atomic structure calculations. [Preview Abstract] |
Tuesday, June 14, 2011 11:54AM - 12:12PM |
B6.00005: Strong-field dissociation dynamics of NO$^{2+}$: A multiphoton electronic or vibrational excitation? Bethany Jochim, E. Wells, M. Zohrabi, B. Gaire, U. Abulikemu, K.D. Carnes, B.D. Esry, I. Ben-Itzhak A 3-D momentum imaging technique is employed to study intense ultrafast laser-induced dissociation of a metastable NO$^{2+}$ beam. We focus on N$^{+ }$+ O$^{+}$ coincidences and explore possible dissociation pathways using estimates of the initial vibrational population and transition rates between the X $^{2}\Sigma ^{+ }$and A $^{2}\Pi $ states together with kinetic energy release and angular distribution spectra. Our analysis suggests that lower intensity pulses ($<$10$^{15}$ W/cm$^{2})$ drive perpendicular transitions between these states. Higher intensity pulses ($\sim $10$^{16}$ W/cm$^{2})$, on the other hand, yield a prominent contribution from molecules breaking parallel to the polarization. While the results are preliminary, an intriguing possibility is that this feature is due to a direct 2-photon transition to the vibrational continuum of the X $^{2}\Sigma ^{+}$ state, $i.e.$, a multiphoton vibrational excitation on the electronic ground state. [Preview Abstract] |
Tuesday, June 14, 2011 12:12PM - 12:30PM |
B6.00006: Causality and relativistic localization in one-dimensional Hamiltonians Benjamin Shields, R. Grobe, Q. Su We compare the relativistic time evolution of an initially localized quantum particle obtained from the relativistic Schr\"odinger, the Klein-Gordon and Dirac equation. By computing the amount of the spatial probability density that evolves outside the light cone we quantify the amount of causality violation for the relativistic Schr\"odinger Hamiltonian. We comment on the relationship between quantum field theoretical transition amplitudes, commutators of the fields and their bilinear combinations outside the light cone as indicators of a possible causality violation. We point out the relevance of the relativistic localization problem to this discussion and comment on ideas about the supposed role of quantum field theory as a vehicle of making a theory causal by introducing antiparticles. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700