High-dimensional intracity quantum cryptography with structured photons
High-dimensional intracity quantum cryptography with structured photons
复制标题
DOI：
10.1364/optica.4.001006
复制
发表时间：
2017-09-20
期刊：
影响因子：
10.4
通讯作者：
Karimi, Ebrahim
中科院分区：
文献类型：
--
作者：
Sit, Alicia;Bouchard, Frederic;Karimi, Ebrahim
量子密钥分发(QKD)承诺信息理论上的安全通信，并且已经处于商业化的边缘。下一步将实现高维协议，以提高抗噪声能力和提高数据速率。到目前为止，还没有在实验室外进行单光子高维量子密钥分配的实验验证。在这里，我们报道了在渥太华上空0.3公里的湍流自由空间链路中，利用自旋角动量和轨道角动量的光子自由度，实现了这样一个单光子QKD系统。光学角动量的这种组合允许我们创建一个4维量子态；其中，使用高维BB84协议，获得了11%的量子误码率，对应的密钥速率为0.65比特/经过筛选的光子。相比之下，对于二维结构光子的情况，获得了5%的错误率和0.43比特的秘密密钥率。因此，我们证明，即使在没有主动波前校正的情况下，即使在适度的湍流中，高维光子态也有利于安全地传输更多的信息。这为现实条件下的星内高维量子通信开辟了道路。(C)2017年美国光学学会
Quantum key distribution (QKD) promises information-theoretically secure communication and is already on the verge of commercialization. The next step will be to implement high-dimensional protocols in order to improve noise resistance and increase the data rate. Hitherto, no experimental verification of high-dimensional QKD in the singlephoton regime has been conducted outside of the laboratory. Here, we report the realization of such a single-photon QKD system in a turbulent free-space link of 0.3 km over the city of Ottawa, taking advantage of both the spin and orbital angular momentum photonic degrees of freedom. This combination of optical angular momenta allows us to create a 4-dimensional quantum state; wherein, using a high-dimensional BB84 protocol, a quantum bit error rate of 11% was attained with a corresponding secret key rate of 0.65 bits per sifted photon. In comparison, an error rate of 5% with a secret key rate of 0.43 bits per sifted photon is achieved for the case of 2-dimensional structured photons. We thus demonstrate that, even through moderate turbulence without active wavefront correction, high-dimensional photon states are advantageous for securely transmitting more information. This opens the way for intracity high-dimensional quantum communications under realistic conditions. (C) 2017 Optical Society of America