Single emitters allow for exciting research in modern physics. Not only as single emitters are nanometer-sized, they also hold intrinsic non-linearities in the interaction with light. Furthermore, once excited, they tend to emit single photons, one by one which are intrinsic quantum states.

One major work horse in the group is the research on single organic molecules. They can be tailored by means of organic chemistry and cover the entire visible spectrum. Under liquid helium temperatures a few of these molecules are spectrally well behaved, i.e. they emit a narrow spectrum of visible light and also they can be pretty bright: A single organic molecule can be observed by the bare human eye.

The hybridization of single emitters and atomic vapors has been pioneered by the group in the past years. We construct single photon sources which are resonant to atomic species such as sodium, rubidium and potassium.

Single solid-state emitters also offer great opportunities for quantum sensing at the nanoscale. Well known is the negatively charged nitrogen-vacancy center in diamond.