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Atomic Physics Seminars

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Events During the Week of January 22nd through January 29th, 2017

Monday, January 23rd, 2017

No events scheduled

Tuesday, January 24th, 2017

A Brief History of Time(keeping): Metrology and quantum simulation with optical lattice clocks
Time: 12:00 pm
Place: 5280 Chamberlin Hall
Speaker: Shimon Kolkowitz, JILA - University of Colorado Boulder
Abstract: Optical lattice clocks (OLCs) are now the most stable and accurate timekeepers in the world, with fractional accuracies equivalent to neither losing nor gaining a second over the entire age of the universe. This unprecedented level of metrological precision offers sensitivity to new quantum, many-body, and fundamental physics effects, opening the door to exciting and unusual applications. However, the current generation of OLCs are now approaching their classical limits, requiring quantum science techniques to reach the next frontier in clock performance.

This talk will provide an introduction to how and why time is measured, with an emphasis on OLCs and their applications. I will discuss recent progress on pushing OLCs to even greater levels of precision, as well as prospects for future improvement. I also will present results from a recent experiment in which we harnessed the precision of an OLC to simulate complex condensed matter phenomena. Finally, I will give a brief overview of potential future applications of OLCs, including gravitational wave detection, tests of general relativity, and searches for physics beyond the Standard Model.
Host: Thad Walker
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Wednesday, January 25th, 2017

No events scheduled

Thursday, January 26th, 2017

From fundamental physics to aspects of photosynthesis: Controlling and studying complex quantum systems
Time: 12:00 pm
Place: 5280 Chamberlin Hall
Speaker: Boerge Hemmerling, UC Berkeley
Abstract: The answer to many scientific questions ranging from fundamental physics to aspects of photosynthesis lie in the study of quantum systems. A requirement for such studies is often to initialize the systems, manipulate them and read them out. However, many of the systems with interesting applications tend to have a complex level structure rendering these requirements difficult to meet.

In this talk, I will discuss experimental strategies to control complex ions and molecules for which standard trapping, cooling and state manipulation methods fail. In particular, I will discuss how complex ions, such as Ti+ or Fe+, can be studied and used to place limits on the temporal variation of fundamental constants. Moreover, I will present a strategy to laser cool the diatomic molecule calcium monofluoride, a precursor to produce a degenerate dipolar quantum gas. Finally, I will show how strings of ions can be used to emulate processes relevant for transport phenomena in light harvesting processes.

I will conclude with a discussion on how to control and study two further quantum systems: electrons and aluminum chloride. Electrons can be stored in a novel two-frequency Paul trap, constituting the first step towards electron quantum computing; such a trap has, moreover, the potential to advance studies on matter-antimatter asymmetries by improving antihydrogen production. Furthermore, I will explain a laser cooling scheme for aluminum chloride, a molecule with excellent prospects for generating high phase-space density clouds at ultracold temperatures to study the physics of degenerate dipolar quantum gases.
Host: thad Walker
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Friday, January 27th, 2017

Ultralow-Power Nonlinear Optics using Metastable Xenon in a Cavity
Time: 10:00 am
Place: 5310 Chamberlin
Speaker: Garrett Hickman, UMBC
Abstract: Single-photon cross phase shifts and other single-photon nonlinearities have numerous applications in all-optical quantum information processing. Several groups have experimentally achieved single-photon phase shifts on the order of pi. However, nonlinearities weaker than this have important applications as well. We introduce the idea of using metastable xenon gas in a high-finesse cavity to produce weak single-photon nonlinearities. This relatively simple and robust system avoids problems associated with the accumulation of alkali atoms on mirror surfaces, and is capable of approaching the strong coupling regime of cavity quantum electrodynamics. We demonstrate the feasibility of our approach with two proof-of-principle demonstrations, by measuring absorption saturation and cross-phase modulation using a cavity of moderately high finesse F=3,000. We find that the nonlinear effects occur at ultralow input power levels, proving that the presence of the cavity strongly enhances the inherent optical nonlinearities of metastable xenon. We close our discussion by reviewing our recent progress in building an improved cavity system, which is expected to produce enhanced single photon cross phase shifts.
Host: Saffman
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