Professor Stefan Willitsch, University of Basel, Switzerland
Quantum metrology with single trapped molecules
Precision-spectroscopic investigations of molecular systems have recently gained considerable interest in the context of a variety of applications in fundamental physics. These include setting stringent constraints on the magnitude of the dipole moment of the electron, exploring potential time variations of fundamental constants and developing new types of highly precise clocks. In the talk, we will review recent progress on precision measurements on single trapped molecules focusing on the nitrogen molecular ion N2+. We will touch on the specific properties of molecules in the context of frequency metrology, discuss aspects of state initialisation and control, and highlight recently developed quantum protocols which enable vastly improved measurement sensitivities in experiments on molecules. We will also discuss a recently established prototype network for precision frequency transfer and comparison in Switzerland which is intended to form the nucleus of a wider national infrastructure for frequency metrology. Finally, we will present results on the applications of these developments in the spectroscopy of dipole-forbidden rovibrational transitions in N2+ which are of particular interest for frequency metrology.