title: Afterpulse-like phenomenon of superconducting single photon detector in high speed quantum key distribution system.
abstract: 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.
authors: Quantum ICT Laboratory, National Institute of Information and Communications Technology, 4-2-1 Nukuikitamachi, Koganei, Tokyo 184-8795, Japan.
authors: M
authors: M
authors: Fujiwara
authors: A
authors: A
authors: Tanaka
authors: S
authors: S
authors: Takahashi
authors: K
authors: K
authors: Yoshino
authors: Y
authors: Y
authors: Nambu
authors: A
authors: A
authors: Tajima
authors: S
authors: S
authors: Miki
authors: T
authors: T
authors: Yamashita
authors: Z
authors: Z
authors: Wang
authors: A
authors: A
authors: Tomita
authors: M
authors: M
authors: Sasaki
mesh_terms: D000669:Amplifiers, Electronic; D003198:Computer Simulation; D004867:Equipment Design; D005336:Fiber Optic Technology; D017785:Photons; D011789:Quantum Theory; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*