Group of Applied Physics, University of Geneva, 1211 Geneva 4, Switzerland.
Phys Rev Lett. 2010 Aug 13;105(7):070501. doi: 10.1103/PhysRevLett.105.070501. Epub 2010 Aug 12.
In device-independent quantum key distribution (DIQKD), the violation of a Bell inequality is exploited to establish a shared key that is secure independently of the internal workings of the QKD devices. An experimental implementation of DIQKD, however, is still awaited, since hitherto all optical Bell tests are subject to the detection loophole, making the protocol unsecured. In particular, photon losses in the quantum channel represent a fundamental limitation for DIQKD. Here we introduce a heralded qubit amplifier based on single-photon sources and linear optics that provides a realistic solution to overcome the problem of channel losses in Bell tests.
在设备无关量子密钥分发（DIQKD）中，利用违反贝尔不等式来建立共享密钥，该密钥独立于 QKD 设备的内部工作原理而安全。然而，由于迄今为止所有光学贝尔测试都存在检测漏洞，因此仍然需要进行 DIQKD 的实验实现，这使得该协议不安全。特别是，量子信道中的光子损耗是 DIQKD 的一个基本限制。在这里，我们引入了一种基于单光子源和线性光学的被选量子比特放大器，为克服贝尔测试中通道损耗问题提供了一种现实的解决方案。
