Measuring the stability of fundamental constants with a network of clocks.

The QSNET collaboration aims to measure variations in the fundamental constants of the Standard Model, providing potential evidence of new physics and insights into the nature of dark matter and dark energy. QSNET utilises a network of atomic and molecular clocks with unprecedented sensitivity to such constants. The sensitivity of a certain atomic or molecular transition, on which the clocks in the network are based, to a fundamental constant x is characterised by a sensitivity coeicient, K2. Frequency ratios between clocks in the network are measured and used to determine variations of fundamental constants.The main objective of this PhD project is to assist in the design, development and construction of a Calcium-Fluoride (CaF) Molecular Optical Lattice Clock, a first of its kind. The clock will be
based on the fundamental vibrational transition in CaF, with a frequency of 17.472THz and a linewidth of 0.7Hz. The Molecules will initially be trapped by a Magneto Optical Trap then sub-doppler cooled to micro-Kelvin temperatures. The Molecules are then loaded into an optical lattice to ensure that they are subject to the Lamb-Dicke regime, which eliminates first order Doppler shifts, maintaining the clock transition's low linewidth. A 3D lattice will also eliminate collisional affects. Finally, in order to interrogate the clock transition, a pair of Raman lasers will be used, each locked to a cavity for frequency tability. Once complete, the clock will be integrated into the QSNET network of clocks, culminating in the National Physics Laboratory where frequencies can be compared to test for variations.