Electromagnetic radiation emanating from the molecular nanomagnet Fe$_{8}$

Photons emitted by transition between the discrete levels of single molecular magnets have an interesting property: their wave length can be similar to that of the sample size. This is the elementary condition for Dicke's super-radiance. In this radiative process a short intense pulse of light from a molecular system appears as a result of enhanced spontaneous emission rate due to interactions via the electro-magnetic field. Consequently, several investigators have been looking for this type of radiation in the molecular magnet Mn$_{12}$, where energy bursts were reported after magnetic avalanches. We investigate the same phenomenon in the Fe$_{8}$ molecule. Unlike in Mn$_{12}$ we found energy bursts each time there is a jump in the magnetization, confirming their quantum nature. A series of tests indicated that photons carry out the energy. These photons obey the elementary conditions for super-radiance.