Institute of Electronic Structure and Laser, FORTH, GR-71110 Heraklion, Crete, Greece.
Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
Phys Rev Lett. 2018 Sep 21;121(12):123605. doi: 10.1103/PhysRevLett.121.123605.
We propose an efficient free-space scheme to create single photons in a well-defined spatiotemporal mode. To that end, we first prepare a single source atom in an excited Rydberg state. The source atom interacts with a large ensemble of ground-state atoms via a laser-mediated dipole-dipole exchange interaction. Using an adiabatic passage with a chirped laser pulse, we produce a spatially extended spin wave of a single Rydberg excitation in the ensemble, accompanied by the transition of the source atom to another Rydberg state. The collective atomic excitation can then be converted to a propagating optical photon via a coherent coupling field. In contrast to previous approaches, our single-photon source does not rely on the strong coupling of a single emitter to a resonant cavity, nor does it require the heralding of collective excitation or complete Rydberg blockade of multiple excitations in the atomic ensemble.
我们提出了一种有效的自由空间方案，用于在明确定义的时空模式中产生单光子。为此，我们首先将单个源原子制备到激发的里德堡态。源原子通过激光介导的偶极-偶极交换相互作用与大量基态原子相互作用。使用具有啁啾激光脉冲的绝热通道，我们在集体中产生单个里德堡激发的空间扩展自旋波，同时源原子跃迁到另一个里德堡态。然后，通过相干耦合场将集体原子激发转换为传播光光子。与以前的方法相比，我们的单光子源不依赖于单个发射器与共振腔的强耦合，也不需要集体激发的 heralding 或原子集体中多个激发的完全里德堡阻塞。
