Erbium Ions in solids are exceptional candidates to store and process quantum information on timescales beyond other platforms. Their fine structure and Zeeman splitting allows them to be coupled to both optical and microwave photons. This latter capability makes them a powerful choice to store the information of superconducting circuits, which can be done thanks to the strong collective coupling previously achieved in other groups.
In our team, Kritika MUNDEJA, 
Sakshi MISHRA, HAN Zhikun and BAO Sicheng are leveraging the Refocusing of Amplified Spontaneous Emission (RASE) to generate Microwave-Erbium entanglement. For this, they make use of our ultra-fast microwave measurement setup, our dilution refrigerator and nanofabrication capabilities.