  Description of superradiance of few quantum emitters with non-radiative decay
in terms of quantum states is presented. Quantum efficiencies (QE) of SR of two
and three emitters are calculated and compared with the case of two and three
independent emitters. Maximum increase in QE is 8% for two emitters and 16% for
three emitters, it is reached at certain ratios between non-radiative and
radiative rates. Approach can be generalized with inclusion of the incoherent
pump, dephasing and delay in emitter-emitter interaction.
