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Economic Stimulus : Valorization of Single Photon Detectors and Quantum Key Distribution Systems Hugo Zbinden Group of Applied Physics (GAP), UNIGE NCCR Transfert Projects (GAP – id Quantique): High Speed Single Photon Counting Module (H.Z.) Second Generation QKD Engine (N. Gisin ).
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Economic Stimulus:Valorization of Single Photon Detectors and Quantum Key Distribution SystemsHugo ZbindenGroup of AppliedPhysics (GAP), UNIGENCCR Transfert Projects (GAP – id Quantique):High Speed Single Photon CountingModule (H.Z.)Second Generation QKD Engine (N. Gisin)
ID Quantique • Spin-off from GAP basedin Geneva • Founded in 2001 • 17 employees ( 4 from GAP) • Customer base on 6 continents 3 business units Instrumentation Business Unit Technology Encryption Business Unit • Two product lines • High-Speed Encryption • Quantum Cryptography - Single-photon detectors RNG Business Unit Services (training, installation, maintenance)
NCCR-QP Project 4:Single Photon Detectors InGaAs Avalanche photon detectors Supraconducting Detectors Hybridschemes: Upconversion detectors, photon numberresolvingetc
InGaAs Avalanche Photo Diode Performance: = 10-20% Pdark= 1000/s Timing jitter = 300 ps Max. Rate = 100 kHz Si-APD: 50 % cdark= 10/s 50 ps 10 MHz
Afterpulsingis a problem Mitigation: - deadtime - rapidquenching or short gates -> limited count rate, duty cycle < 1
Sinus gatingallowshigh count rates Pulse rate 1.25 GHz, gatewidth ~130ps (FWHM)
Novel APD withnegative feedback for free running operation • Internalresistorquenchesrapidly the avalanche • Slow recharging • -> niceresults in free running mode:poster of Tommaso Lunghi
Versatile detector module Specifications: Gated mode up to 100 MHz Variable gatelength 1ns to 10ns Free running Integratedcounters, clock, variable delayetc Inputs and outputs in NIM, ECL, TTL etc «cool» user interface Easyupgradablewith new functions (TDC, histogram)
id 210 as a whole People: Jun Zhang (physicist), APD characterisation, measurements Claudio Barreiro (engineer), pulser electronics Oliver Guinnard (engineer), design, electronics, mechanics Bernard Clausen (engineer), electronics Alexis Rochas (physicist), concept and testing Jean-Benoit Page (engineer), programming, user interface Laurent Monat (engineer), electronics and FPGA Tony Matteo (engineer), production
Quantum Key Distribution Quantum Cryptography is not a new coding method, it allows to create a secret key Security is based on the laws of quantum physics “A measurement perturbs the system in an irreversible way”. A spy listening to the “quantum communication”, disturbs the system and will be detected.
0 1 0 0 The basic idea is simple Alice Eve Bob Error with 25 % probability • The error rate (QBER) indicates the presence of Eve and the information she possesses(in practice typical QBER ~1-2%) 1
Alice Bob Qubits Transmission Quantum channel (losses) Raw key Public channel Basis Reconciliation Sifted key QBER estimate Error correction Privacy amplification Key Key Key Distillation
Smolin and Bennett IBM 1989 id Quantique 2006 2 (dark) fibers Distance 100km 100 MHz Ethernet Not One Time Pad!
The plug & play system is getting old • Faint laser BB 84, two way scheme • 5 MHz pulse rate • 1 kbit/s secret bit rate @ 25km presented at CeBit02 with guest star Sandra Pochon!
Coherent-One-Way (COW) scheme • Coherentfaint laser pulses (µ~0.5) • 150 km of installed and standard fibres, 43dB of losses • SECOQC 2008 (Vienna)
Industrial COW prototype: 1000 times higher bit rates 625 MHz rate (1.25 GHz pulse rate) 1 Mbit/s secret key rate @ 25km WDM of quantum and classicalchannel real time distillation (FPGA) security, finitekeyanalysis
The QCrypt Concept 100 Gb/s 1 Mb/s OTP High-speed Quantum Key Distribution + 40 – 100Gbps enCRYPTion + WDM
Tfwhm=138 ps QKD EngineResults: 250 ps Intensity modulation Sinus gating detector Short gates Lowafterpulsing High count rates
QKD and WDM Bob Bob Alice Alice Classical communication channel • Goal: Key distribution and high speed data encryption over a single optical fibre • Commercial QKD (plug & play) and AES-encryptors (256 bits keys, 1 Gbps rate) New Journal of Physics 12 (2010) 063027 Dedicated quantum channel
Fiber attenuation: -0.207 dB/km Detection efficiency: 0.07 Dark count rate: 510-6 ns-1 Dead time: 10 s DWDM isolation: 82 dB Experimental Results