Erbium Ions defects in solids are candidates of choice for Quantum Technologies such as Quantum computing (in measurement based quantum computing) and quantum networks (quantum repeaters, memories…). These defects are parts of the field of Rare-Earth ions, with the particularity of having their main transition frequency at 1550 nm, where commercial telecommunication fibers attenuate the least. Therefore, technologies leveraging Erbium Ions can be readily integrated in existing infrastructures and carry quantum signals over kilometers at room temperature. Finally, these ions are also sensitive to magnetic fields, so that their Zeeman splitting is in the microwave regime. This latest part allows Rare-Earth ions to communicate with both superconducting circuits and optical Quantum Technologies.
In our team, Pavel DMITRIEV Karthik DASIGI, 
WO Kah Jen and KONG Lingda are investigating how to reach the novel strong-collective regime between a large ensemble of Erbium Ions and high-quality ring resonators made of Lithium Niobate on Insulators. This material forms the backbone of integrated photonics, thanks to their wide transparency windows and their good electro-optic effect. Our collaborator helps us develop state-of-the-art resonators (Q>1M), which sets us on par with leading groups in photonics.
The team leverages the lab’s capabilities given by our dilution refrigerator, nanopositioners, fast modulators, Heterodyne/homodyne measurement, chip bonding, nanofabrication and more to achieve this regime and develop ground breaking new quantum technologies.
Pictures:
SEM, bonded chips, attocubes, optical table