Speaker
Description
The narrowness of the optical transitions of rare-earth-ion dopants makes them highly sensitive probes of their environment. When rare-earth ions are doped into a magnetic crystal, they display an enriched optical spectrum, with features that can only be explained by including the spins of the host crystal in the model. We explored optical absorption spectroscopy of erbium-doped Gd$_2$SiO$_5$, using the erbium dopants as a probe for the magnetic phases of the host material. We determined that the host crystal orders antiferromagnetically below a Néel temperature of 1.86 K, and found a range of magnetic phase transitions in temperature and applied magnetic field. The previously unknown magnetic ordering is confirmed by neutron diffraction with “hot” neutrons at the Institut Laue–Langevin.
Despite the erbium dopants being surrounded by environmental spins with large magnetic moments, they show long optical coherence times up to 0.4 ms, which we measured with photon echoes. Because the host spins have effectively fixed orientations due to the long-range magnetic order, the host crystal can still be a magnetically quiet environment for dopants.
| I am the presenting author | Yes |
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