Merging "nano", rare-earths, and nonlinear crystals: key technology for large-scale quantum networks

融合“纳米”、稀土和非线性晶体：大规模量子网络的关键技术

• 批准号: RGPIN-2015-05477
• 负责人: Tittel, Wolfgang
• 金额: $ 5.17万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633161
• 关键词: Merging; nano; rare; earths; nonlinear

The economic, political, and social well-being of Canada depends crucially on secure electronic communications, e.g. for e-banking, e-health, e-commerce, and e-government. Yet, current public key crypto systems rely on unproven assumptions about computational complexity, are susceptible to algorithmic advances and better classical computer technology, and will become obsolete with the advent of the quantum computer. Hence, the secrecy of messages encoded and sent in the past or present, even if still ensured today, is vulnerable to future improvements in code breaking, which may lead to decoding of recorded messages with insufficient protection before they lose importance. Quantum key distribution (QKD), which employs individual photons prepared in specific quantum states as carriers of information, promises the ultimate solution to these problems: security that cannot be compromised by new technology. Yet, as photons get lost during transmission, and amplifiers cannot be used due to a fundamental restriction of quantum mechanics known as the no-cloning theorem, QKD currently faces a distance limit of around 200 km. Interestingly, this limit can be removed through not-yet-existing quantum repeaters.

加拿大的经济，政治和社会福祉取决于安全的电子通信，例如用于电子银行，电子卫生，电子商务和电子政务。然而，当前的公共密钥加密系统依赖于对计算复杂性的未经证实的假设，容易受到算法进步和更好的经典计算机技术的影响，并且随着量子计算机的出现，将变得过时。因此，即使今天仍然确保了过去或现在，秘密编码和发送的消息也很容易受到未来的代码破坏的改进，这可能会导致在失去重要性之前对记录的消息进行解码。量子密钥分布（QKD）采用以特定量子状态制备的单个光子作为信息的载体，它有望解决这些问题的最终解决方案：新技术不能损害的安全性。然而，由于在传输过程中光子丢失，并且由于对称为无粘性定理的量子力学的基本限制，因此无法使用放大器，因此QKD目前面临的距离限制约为200 km。有趣的是，可以通过尚不存在的量子中继器来删除此限制。