Understanding atomic interactions in an optical lattice clock and using them to study many-body physics

Author
Abstract
<p>Strontium optical lattice clocks at JILA recently demonstrated record-high accuracy and stability.\&nbsp;<span style="font-size: 13px; line-height: 1.6em;">These advances were enabled by an ultrastable laser with fractional frequency stability of\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">1 x 10<sup>-16</sup> at 1 second. This laser allows us to study systematic shifts of the <sup>1</sup>S<sub>0</sub> to <sup>3</sup>P<sub>0</sub> clock transition\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">with unprecedented precision. Density-dependent frequency shifts represent an unavoidable\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">perturbation for clocks based on many atoms. Our studies of atomic interactions in an optical\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">lattice clock system uncover the nature of these interactions and reveal important many-body\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">atomic correlation effects in this open quantum system. By extending our measurements to all ten\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">nuclear-spin sublevels of the clock states, we observe the first direct evidence of SU(N) symmetric\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">interactions in alkaline earth(-like) atoms. Using the techniques we developed in these studies, we\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">also demonstrate a novel technique for measuring the frequency noise spectrum of an ultrastable\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">laser. We discuss designs for the future direction of our experiment which will place <sup>87</sup>Sr atoms\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">within a high finesse cavity that is resonant on the <sup>1</sup>S<sub>0</sub> to <sup>3</sup>P<sub>1</sub> transition. We will use this system\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">to study collective effects in cavity quantum electrodynamics. Most notably, strong atom-cavity\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">coupling can enhance the spectroscopic sensitivity of our clock by creating spin-squeezed states via\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">quantum non-demolition measurements. As a precursor to future work studying cavity-mediated\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">collective behavior, we use the unique atomic structure of <sup>88</sup>Sr to investigate free-space retarded\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">dipolar coupling in an optically thick sample of atoms.</span></p>
Year of Publication
2014
Degree
Ph.D.
Number of Pages
163
Date Published
2014-09
University
University of Colorado Boulder
City
Boulder
Advisors - JILA Fellows
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