Superfluorescence and spontaneous formation of macroscopically extended coherent states

by Dr Federico Chiossi (Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie, Paris)

Thursday 19 Oct 2023, 12:00 → 13:30 Europe/Madrid

IFAE Seminar Room (Face-to-face Only)

The Dark Matter nature and the neutrino absolute mass and features are among the most long- standing questions that Particle Physics has been facing. The interactions of these particles with "ordinary" matter are extremely weak and their detection/investigation is indeed challenging. To overcome the current detection limits, the use of atoms/molecules in a coherent state has been proposed as their cooperative behavior is expected to enhance the detection sensitivity by a factor N, where N is the number of atoms/molecules in the coherent state. Atomic coherence can be prepared in different ways and in this talk, we will discuss one of these possibilities. Actually, under certain conditions, atomic coherence can develop spontaneously in an ensemble of identical excited atoms, and since even the spontaneous photon emission experiences the N-enhancement, a burst of coherent radiation called "superfluorescence" is concurrently produced. Our work has been focused on the study of the optical superfluorescence generated by erbium-doped crystals at cryogenic temperatures. We have observed and characterized the spontaneous formation of coherent states composed of more than 10^12 erbium ions and the related acceleration of the spontaneous emission rate by more than one million times.