JILA Thesis Defense

Entangled two-photon absorption (E2PA) is a process in which entangled photon pairs are used instead of a pulsed laser to excite a two-photon transition. The correlation of these photons in time and space may improve the excitation efficiency. In this work, we develop experimental apparatuses that enable sensitive measurements of E2PA via both transmittance and fluorescence-based schemes. We show strong evidence that E2PA cross sections are several orders of magnitude lower than many prior reports claimed.

Abstract: To date, neutral atom optical lattice clocks have demonstrated the highest precision measurements of fractional frequency shifts. State-of-the-art optical oscillators employing cryogenic reference cavities have been used to push this frontier, enabling record-level stabilities and resulting in foundational advances in optical frequency metrology. The fundamental performance of cryogenic cavities utilizing crystalline spacers and substrates has been limited by the Brownian thermal noise associated with mechanical dissipation of the mirror coatings.

Abstract:

Abstract: Ultracold molecules have rich internal structure and tunable dipolar interactions, making them an exciting platform for studying quantum many-body physics. However, controlling molecular interactions, especially chemical reaction losses, has remained an experimental challenge. We demonstrate two approaches for tuning molecular interactions: strong 2D confinement and electric-field-induced shielding resonances.

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https://cuboulder.zoom.us/j/94106763212

Meeting ID: 941 0676 3212
Passcode: coldmole

Abstract: Ultracold polar molecules, which have complex internal state structures and dipole moments tunable with external electric fields, are a promising system for studying many-body physics. Producing degenerate molecules and observing quantum effects has been prevented by high initial temperatures and rapid loss from chemical reactions. In this talk, I describe the creation of degenerate potassium-rubidium (KRb) molecules by pairing in an atomic mixture.