Observation of narrow, state-resolved nuclear transitions in ThF4 thin films

Establish narrow, quantum-state-resolved laser spectroscopy of the 229mTh nuclear transition in ThF4 thin films by increasing the emitter participation fraction and reducing inhomogeneous broadening associated with amorphous structure to enable resolution of individual nuclear sublevels.

Background

Although the authors observed the nuclear transition in ThF4 thin films, they report that narrow, state-resolved transitions analogous to those seen in crystal hosts have not yet been observed in the thin-film samples.

They attribute this to low participation fraction and likely inhomogeneous broadening from amorphous characteristics, indicating the need for material processing and spectroscopic advances to reach state-resolved resolution.