  We investigate a hybrid quantum system that consists of a superatom coupled
to a surface phonon-polariton. We apply this hybrid quantum system to subtract
individual photons from a beam of light. Rydberg atom blockade is used to
attain absorption of a single photon by an atomic microtrap. Surface
phonon-polariton coupling to the superatom then triggers the transfer of the
excitation to a storage state, a single Rydberg atom. The approach utilizes the
interaction between a superatom and a Markovian bath that acts as a controlled
decoherence mechanism to irreversibly project the superatom state into a single
Rydberg atom state that can be read out.
