JILA Thesis Defense

Soft X-ray Generation Using Mid-Infrared Femtosecond Lasers at High kHz Repetition Rates

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AbstractHigh harmonic generation is a unique short wavelength light source with high spatial and temporal coherence, enabling ultrafast pump-probe studies of dynamics in chemical reactions, biological systems, and technologically relevant materials. For soft x-ray generation, this requires ultrafast lasers operating at high pulse energy and high repetition rate in the mid-infrared spectral region, which remain a challenging technology.

Designing sensors with tensioned silicon nitride micromechanical resonators

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Abstract: Mechanical resonators based on stressed silicon nitride have both exemplary optical and mechanical properties. Through targeted shaping of the resonator geometry, the dissipative properties of these resonators can be enhanced, yielding micromechanical devices that maintain coherence for up to billions of oscillation periods.

Programmable arrays of alkaline earth atoms: qubits, clocks, and the Bose-Hubbard model

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Abstract: Neutral atoms trapped in optical tweezer arrays have emerged as a promising platform for quantum computing, and for the analog simulation of various spin models. In this work, we apply the programmable control provided by optical tweezer arrays to new domains in quantum science by means of interfacing optical tweezers with a Hubbard-regime optical lattice, and extending the optical tweezer toolbox to new atomic species (namely alkaline earth atoms).

Single molecule ligand binding kinetics and environmental adaptations in lysine riboswitches

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Abstract: Riboswitches are important RNA structures in bacteria and some eukaryotes that can bind a ligand to toggle between conformations that allow or terminate transcription, translation, or splicing. We study folding kinetics and thermodynamics in the B. subtilis and T. maritima lysine riboswitches via single molecule TIRF microscopy. We show that riboswitch folding is exothermic with a large entropic cost, which we attribute to increased binding pocket rigidity upon lysine binding.