Reducing decoherence in optical and spin transitions in rare-earth-ion doped materials

TL;DR

This paper identifies transitions with zero first-order Zeeman shift in rare-earth-ion doped materials, aiming to reduce decoherence and enhance quantum memory and cavity QED applications.

Contribution

It locates ZEFOZ transitions in Pr3+:YAG and Er3+:Y2SiO5 using published data and Raman heterodyne spectroscopy, advancing coherence time improvements.

Findings

Identified ZEFOZ transition points in Pr3+:YAG and Er3+:Y2SiO5

Measured excited state parameters via Raman heterodyne spectroscopy

Highlight potential for improved quantum memories and cavity QED

Abstract

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.