IAP Seminar (Probing Fundamental Physics with Precision Molecular Spectroscopy)
Date : May 30, 2025 11:00 ~ 12:00
Speaker : Dr. Samuel Meek (University of Oklahoma)
Professor : Prof. Yong-il Shin
Location : 22-412
Probing Fundamental Physics with Precision Molecular Spectroscopy
Precise measurements of molecular transition frequencies can provide a means to test fundamental physical questions, such as whether there are additional forces between the nuclei that are not predicted by the standard model or if the masses of elementary particles vary over time. Such measurements can also help determine physical constants more precisely and provide data that can be used to better interpret astronomical spectra. In my lab, we have developed an apparatus for determining vibrational and electronic transition frequencies of isolated small molecules with high precision. The central component of this apparatus is a precision laser system containing narrow-linewidth reference and spectroscopy lasers linked to each other and to an atomic clock reference using an optical frequency comb. So far, we have used this apparatus to investigate electronic transitions in OH, OD, and SH, as well as vibrational transitions in HD and D₂. In all of these measurements, we have been able to determine the absolute transition frequencies with orders of magnitude higher precision than previously reported and, in some cases, detect systematic errors in earlier, less precise measurements. In future measurements, trapping the molecules and applying quantum techniques can help to achieve narrower transition linewidths and improve the precision further.
Precise measurements of molecular transition frequencies can provide a means to test fundamental physical questions, such as whether there are additional forces between the nuclei that are not predicted by the standard model or if the masses of elementary particles vary over time. Such measurements can also help determine physical constants more precisely and provide data that can be used to better interpret astronomical spectra. In my lab, we have developed an apparatus for determining vibrational and electronic transition frequencies of isolated small molecules with high precision. The central component of this apparatus is a precision laser system containing narrow-linewidth reference and spectroscopy lasers linked to each other and to an atomic clock reference using an optical frequency comb. So far, we have used this apparatus to investigate electronic transitions in OH, OD, and SH, as well as vibrational transitions in HD and D₂. In all of these measurements, we have been able to determine the absolute transition frequencies with orders of magnitude higher precision than previously reported and, in some cases, detect systematic errors in earlier, less precise measurements. In future measurements, trapping the molecules and applying quantum techniques can help to achieve narrower transition linewidths and improve the precision further.