Techniques in atomic physics have delivered some of the most precise measurements ever made, with frequency measurements reaching fractional precisions of 10^18 . High precision measurements can be used to test fundamental physics, such as pursuing a variation in fundamental constants. A finite drift in measurable constants such as the proton-to-electron mass ratio (μ) would reveal physics beyond the Standard Model. Rovibrational transitions in molecules offer a way to surpass constraints on the variation of μ placed by atomic measurements. This thesis describes the development of new techniques to measure molecules at unprecedented precision and place new constraints on the variation of μ. We work exclusively with molecular ions, which allows us to trap and interrogate molecules for long periods of time. By simultaneously trapping laser-cooled atomic ions, the molecules are cooled down to temperatures where Doppler shifts are no longer a limiting factor. We describe two different methods to address the initial challenge of producing molecular ions inside the ion trap. In the first method, we construct a molecular beam directed at trapped ions in order to produce novel molecular ions. The second method involves photoionizing molecules entrenched in a molecular beam, for which we developed a new nozzle design. We also make further development toward achieving single molecule spectroscopy, where we aim to achieve the highest precision. We implement a method of producing our highly reactive molecule of interest, AlH+ . We also determine the optimum protocol for a new type of nondestructive, single-molecule quantum state detection, by transferring the internal state information of AlH+ onto a co-trapped Ba + ion. This state detection will ultimately be used to perform high precision spectroscopy. Lastly, we perform an in-depth analysis of the molecular characteristics necessary to provide the best constraint of μ-variation. We propose measuring TeH+, which has unique properties that allow for fast accumulation of statistics. TeH+ is also relatively insensitive to systematic frequency shifts caused by external fields, despite being polar. These new techniques and new molecules will integrate into a growing field of high precision molecular spectroscopy.

Last modified

• 11/20/2019

Creator

• Mark Gabriel Kokish

DOI

• https://doi.org/10.21985/n2-m3z9-rg65

Subject

• Chemistry

Keyword

• Physics

Date created

• 2018-01-01

Resource type

• Dissertation

Rights statement

• In Copyright