Shake The Emitter, Get a Comb
Single photon emitters are among the most important resources in the quantum technology, especially in quantum communications. Nevertheless, the faithful storage and retrieval of these flying qubits, the single-photons, is still challenging. Atomic Frequency Combs (AFC) are amongst the best candidates. Nevertheless, the current proposals for their implementation still suffer some shortages, most importantly the scalability.
In a recent work, published in Physical Review Letters, researchers in the Theoretical Quantum Optics Group have proposed a setup that partly comes up with a solution to this problem. Frequency combs with fine and orderly teeth are generated out of the single photons emitted from a jiggling atom (color center). When the electronic degrees of freedom of a quantum emitter strongly couple to its motion the radiative transitions get modulated so strongly that the outgoing photons start forming a regulatory framework in the frequency domain; a comb. We show that this can indeed happen for a color center in a freestanding hexagonal boron nitride membrane where the coupling is provided by the Casimir effect.