High-dimensional quantum cryptography with twisted light
High-dimensional quantum cryptography with twisted light
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DOI：
10.1088/1367-2630/17/3/033033
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发表时间：
2015-03-20
影响因子：
3.3
通讯作者：
Boyd, Robert W.
中科院分区：
文献类型：
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作者：
Mirhosseini, Mohammad;Magana-Loaiza, Omar S.;Boyd, Robert W.
量子密钥分发(QKD)系统通常依赖于光的偏振进行编码，从而限制了每个光子可以发送的信息量，并对这种系统可以容忍的误码率施加了严格的限制。在这里，我们描述了一个原理证明实验，它表明了基于光场的横向结构的高维量子密钥分配的可行性，允许每个光子传输超过1比特。我们的实现使用了光子的轨道角动量(OAM)和相应的角位置(Ang)的相互无偏的基。我们的实验使用了一个数字微镜装置来快速产生4 kHz的OAM和ANG模，以及一个能够根据OAM和ANG含量对单光子进行分类的模式分类器，其分离效率为93%。通过使用在OAM和ANG基础上编码的七维字母表，我们实现了每个经过筛选的光子2.05比特的信道容量。我们的实验表明，基于空间模式编码的多级量子密钥分发系统除了具有更高的信息容量外，还可以更好地抵抗拦截-重发窃听攻击。
Quantum key distribution (QKD) systems often rely on polarization of light for encoding, thus limiting the amount of information that can be sent per photon and placing tight bounds on the error rates that such a system can tolerate. Here we describe a proof-of-principle experiment that indicates the feasibility of high-dimensional QKD based on the transverse structure of the light field allowing for the transfer of more than 1 bit per photon. Our implementation uses the orbital angular momentum (OAM) of photons and the corresponding mutually unbiased basis of angular position (ANG). Our experiment uses a digital micro-mirror device for the rapid generation of OAM and ANG modes at 4 kHz, and a mode sorter capable of sorting single photons based on their OAM and ANG content with a separation efficiency of 93%. Through the use of a seven-dimensional alphabet encoded in the OAM and ANG bases, we achieve a channel capacity of 2.05 bits per sifted photon. Our experiment demonstrates that, in addition to having an increased information capacity, multilevel QKD systems based on spatial-mode encoding can be more resilient against intercept-resend eavesdropping attacks.