6.2 Superradiance

A. Crubellier, Catherine Bréchignac, Ph. Cahuzac +1 more

In the theoretical stuqy of superradiance, the atoms or molecules are generally considered as two-level systems. However in many experimental situations, this simple assumption is not valid. It is the case, for example, in all experiments exhibiting superradiant beats [1-3]. Moreover, these beats are sometimes due to a specific property of superradiance : the existence of interferences between different atoms. Other examples of multilevel superradiance are encountered each time one observes several superradiant transitions sharing a common level [3,4]. In addition, superradiance is generally observed between degenerate levels, and it has been alreaqy shown experimentally that the level-degeneracy influences the properties of the superradiant light, in particular its polarization characteristics [5].

Michael S. Feld, J. C. MacGillivray

Liangchao Chen, Pengjun Wang, Zengming Meng +5 more

We measure the superradiant emission in a one-dimensional (1D) superradiance lattice (SL) in ultracold atoms. Resonantly excited to a superradiant state, the atoms are further coupled to other collectively excited states, which form a 1D SL. The directional emission of one of the superradiant excited states in the 1D SL is measured. The emission spectra depend on the band structure, which can be controlled by the frequency and intensity of the coupling laser fields. This work provides a platform for investigating the collective Lamb shift of resonantly excited superradiant states in Bose-Einstein condensates and paves the way for realizing higher dimensional superradiance lattices.

Richard Brito, Vítor Cardoso, Paolo Pani

Fatih Dinç, Agata M. Brańczyk

This paper shows how super-superradiance in a waveguide scales with the number of atoms. Usually, superradiance occurs when atoms are separated by distances much smaller than their transition wavelengths, but in waveguide structures, this collective emission phenomenon can persists for even larger periodic separation. Moreover, in a waveguide, this collective decay can become even more superradiant, i.e., super-superradiant. Here, the authors prove that super-superradiance scales linearly with the qubit number, analogous to Dicke superradiance, but with a larger prefactor.

A. Crubellier, Sylvain Liberman, D Pavolini +1 more