Photon blockade and single-photon generation with multiple quantum emitters

Abstract

Generation and manipulation of single photons are at the heart of photon-based quantum information processing. An ensemble of quantum emitters (QEs) as a versatile light-matter interface are very promising for quantum technology such as quantum storage and repeater. However, it is commonly believed that many QEs are unable to create photon blockade and generate single photons with high purity due to the multiexcitation effect. Here, we show efficient photon blockade and single-photon generation with a few to ten QEs by suppressing multiexcitation with a detuned auxiliary cavity. Because the auxiliary cavity induces a strong dipole-dipole interaction among the QEs, these QEs can be treated as a two-level superatom. By coupling this superatom to another collecting cavity, efficient photon blockade with a high transmission is obtained. With the same setup, single-photon emission can also be achieved with yield and purity larger than $90%$ simultaneously even in the bad-cavity limit. Our method may open up a simple route to generate and manipulate single photons on demand.