Fujiwara M, Tanaka A, Takahashi S, Yoshino K, Nambu Y, Tajima A, Miki S, Yamashita T, Wang Z, Tomita A, Sasaki M
Quantum ICT Laboratory, National Institute of Information and Communications Technology, 4-2-1 Nukuikitamachi, Koganei, Tokyo 184-8795, Japan.
Opt Express. 2011 Sep 26;19(20):19562-71. doi: 10.1364/OE.19.019562.
We discuss our estimates of the performance of a superconducting single photon detector (SSPD) in a high speed quantum key distribution (QKD) system. We find that at high repetition operation reflections from the readout circuit at room temperature causes an afterpulse-like phenomenon, and drastically increases the quantum bit error rate (QBER). Such effects are not seen during low frequency operation. By using an amplifier with a small reflection coefficient S11, we succeed in reducing the afterpulse-like phenomenon and increasing a secure key rate.
我们讨论了超导单光子探测器（SSPD）在高速量子密钥分发（QKD）系统中的性能估计。我们发现，在高重复率运行时，室温下读出电路的反射会导致类似后脉冲的现象，并大幅增加量子误码率（QBER）。在低频运行期间未观察到此类效应。通过使用具有小反射系数S11的放大器，我们成功地减少了类似后脉冲的现象并提高了安全密钥率。
