Tiranov Alexey, Strassmann Peter C, Lavoie Jonathan, Brunner Nicolas, Huber Marcus, Verma Varun B, Nam Sae Woo, Mirin Richard P, Lita Adriana E, Marsili Francesco, Afzelius Mikael, Bussières Félix, Gisin Nicolas
Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
Département Physique Théorique, Université de Genève, CH-1211 Genève, Switzerland.
Phys Rev Lett. 2016 Dec 9;117(24):240506. doi: 10.1103/PhysRevLett.117.240506.
Multiplexed quantum memories capable of storing and processing entangled photons are essential for the development of quantum networks. In this context, we demonstrate and certify the simultaneous storage and retrieval of two entangled photons inside a solid-state quantum memory and measure a temporal multimode capacity of ten modes. This is achieved by producing two polarization-entangled pairs from parametric down-conversion and mapping one photon of each pair onto a rare-earth-ion-doped (REID) crystal using the atomic frequency comb (AFC) protocol. We develop a concept of indirect entanglement witnesses, which can be used as Schmidt number witnesses, and we use it to experimentally certify the presence of more than one entangled pair retrieved from the quantum memory. Our work puts forward REID-AFC as a platform compatible with temporal multiplexing of several entangled photon pairs along with a new entanglement certification method, useful for the characterization of multiplexed quantum memories.
能够存储和处理纠缠光子的复用量子存储器对于量子网络的发展至关重要。在此背景下，我们展示并验证了在固态量子存储器中同时存储和检索两个纠缠光子，并测量了十种模式的时间多模容量。这是通过参量下转换产生两个偏振纠缠对，并使用原子频率梳（AFC）协议将每对中的一个光子映射到掺稀土离子（REID）晶体上来实现的。我们提出了间接纠缠见证者的概念，它可以用作施密特数见证者，并且我们用它来通过实验验证从量子存储器中检索到的不止一个纠缠对的存在。我们的工作提出了REID - AFC作为一个与多个纠缠光子对的时间复用兼容的平台，以及一种新的纠缠验证方法，这对于复用量子存储器的表征很有用。
