High precision measurements with cold molecules

Gabriele Santambrogio

Mo, 4 Apr 2016, at 10:00. Aula Querzoli

pdf of the presentation

High-resolution spectroscopy of cold molecules addresses issues of symmetry violation, like in the search for the electric dipole moment of the electron and the studies on energy differences in enantiomers of chiral species; tries to improve the precision to which fundamental physical constants are known and tests for their possible variation in time and space; tests quantum electrodynamics, and searches for a fifth force.

Molecular spectroscopy is essentially a frequency measurement. I will mention the standard methods used to measure a frequency and I will dwell on the general problems encountered while measuring transition frequencies in molecular samples. Further, I will introduce the Bloch's sphere representation and use it to discuss Rabi oscillations and Ramsey spectrometers.

In the second part of the lecture, I will review the available techniques used to produce cold molecular samples. In particular, I will introduce the manipulation of polar molecules with electric fields and describe a Stark decelerator built on a microchip. A series of results in molecular manipulation, optical pumping, and spectroscopic measurement will follow. Finally, I will describe some ongoing experiments aimed at the production of ultracold molecules.

[1] C. Orzel, "Searching for new physics through atomic, molecular and optical precision measurements", Phys. Scr. 86, 068101 (2012)

[2] G. Santambrogio, "Trapping molecules on chips", EPJ Techniques and Instrumentation, 2, 14 (2015)