In many important situations the dominant dephasing mechanism in cryogenic rare-earth-ion doped systems is due to magnetic field fluctuations from spins in the host crystal. Operating at a magnetic field where a transition has a zero first-order-Zeeman (ZEFOZ) shift can greatly reduce this dephasing. Here we identify the location of transitions with zero first-order Zeeman shift for optical transitions in Pr3+:YAG and for spin transitions in Er3+:Y2SiO5. The long coherence times that ZEFOZ would enable would make Pr3+:YAG a strong candidate for achieving the strong coupling regime of cavity QED, and would be an important step forward in creating long-lived telecommunications wavelength quantum memories in Er3+:Y2SiO5. This work relies mostly on published spin Hamiltonian parameters but Raman heterodyne spectroscopy was performed on Pr3+:YAG to measure the parameters for the excited state.
@article{arxiv.1201.4610,
title = {Reducing decoherence in optical and spin transitions in rare-earth-ion doped materials},
author = {D. L. McAuslan and J. G. Bartholomew and M. J. Sellars and J. J. Longdell},
journal= {arXiv preprint arXiv:1201.4610},
year = {2015}
}