González-Tudela A, Paulisch V, Kimble H J, Cirac J I
Max-Planck-Institut für Quantenoptik Hans-Kopfermann-Straße 1, 85748 Garching, Germany.
Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125, USA.
Phys Rev Lett. 2017 May 26;118(21):213601. doi: 10.1103/PhysRevLett.118.213601. Epub 2017 May 24.
Engineering quantum states of light is at the basis of many quantum technologies such as quantum cryptography, teleportation, or metrology among others. Though, single photons can be generated in many scenarios, the efficient and reliable generation of complex single-mode multiphoton states is still a long-standing goal in the field, as current methods either suffer from low fidelities or small probabilities. Here we discuss several protocols which harness the strong and long-range atomic interactions induced by waveguide QED to efficiently load excitations in a collection of atoms, which can then be triggered to produce the desired multiphoton state. In order to boost the success probability and fidelity of each excitation process, atoms are used to both generate the excitations in the rest, as well as to herald the successful generation. Furthermore, to overcome the exponential scaling of the probability of success with the number of excitations, we design a protocol to merge excitations that are present in different internal atomic levels with a polynomial scaling.
光量子态工程是许多量子技术的基础，如量子密码学、量子隐形传态或计量学等。然而，尽管在许多情况下都能产生单光子，但复杂单模多光子态的高效可靠产生仍是该领域长期以来的目标，因为目前的方法要么保真度低，要么概率小。在这里，我们讨论了几种协议，这些协议利用波导量子电动力学诱导的强远程原子相互作用，有效地将激发加载到一组原子中，然后可以触发这些原子产生所需的多光子态。为了提高每个激发过程的成功概率和保真度，原子既用于在其余原子中产生激发，也用于宣告成功产生。此外，为了克服成功概率随激发次数呈指数缩放的问题，我们设计了一种协议，以多项式缩放合并存在于不同内部原子能级的激发。
