Rare-earth doped semiconductors for quantum applications

Rare-earth (RE) doped semiconductors have long been of interest for optoelectronics and spintronics. More recently, they have also been considered for quantum information applications. The materials can offer features similar to those found in RE-doped complex oxide insulators that have often been used in quantum computing and quantum memory experiments. These include sharp optical transitions and excellent coherence properties. The advantage of using semiconducting hosts is that the materials can be controlled electrically, as opposed to just optically. To support progress in this direction, one needs to identify RE-related quantum defects that can be efficient luminescent centers via current injection. In this talk, I discuss recent results for RE defects in semiconductor platforms such as GaN and GaAs obtained from hybrid density-functional calculations. The focus will be on erbium (Er) related defects, as trivalent Er with its optical transitions in the telecom C-band is of particular interest for quantum networking.