EQUAL - Erbium-based silicon quantum light sources

Quantum memories are key components of optical quantum computers and scalable quantum
networks: They are responsible for the central tasks of storing and retrieving quantum information.
The memories must be integrated with quantum light sources, such that distant nodes in a network
can be entangled. The ambition of EQUAL is to demonstrate chip-scale quantum light sources with
embedded quantum memories based on erbium in ultracompact tunable silicon nanocavities.
Erbium in silicon is subject to intense worldwide research right now because erbium is the only
emitter that combines compatibility with semiconductors with long spin coherence time and
emission in the low-loss telecom c-band. However, the platform has one major drawback: Erbium
interacts too weakly with light.