A5021641836- Quantum Information and Cryptography
- Quantum Mechanics and Applications
- Quantum Computing Algorithms and Architecture
- Quantum optics and atomic interactions
- Photonic and Optical Devices
- Advanced Optical Sensing Technologies
- Mechanical and Optical Resonators
- Advanced Fluorescence Microscopy Techniques
- Advanced Fiber Laser Technologies
- Neural Networks and Reservoir Computing
- Laser-Matter Interactions and Applications
- Optical Network Technologies
- CCD and CMOS Imaging Sensors
- Cold Atom Physics and Bose-Einstein Condensates
- Biofield Effects and Biophysics
- Spectroscopy and Laser Applications
- Chaos-based Image/Signal Encryption
- Semiconductor Quantum Structures and Devices
- Photorefractive and Nonlinear Optics
- Atomic and Subatomic Physics Research
- Quantum-Dot Cellular Automata
- Calibration and Measurement Techniques
- Ocular and Laser Science Research
- Semiconductor Lasers and Optical Devices
- Orbital Angular Momentum in Optics
University of Geneva
2015-2024
HES-SO Genève
2022-2023
Jet Propulsion Laboratory
2019
University of Basel
2019
Corning (United States)
2018
ID Quantique (Switzerland)
2017
Pontifical Catholic University of Rio de Janeiro
2008
Geneva College
1997-2007
Swisscom (Switzerland)
1998
Quantum cryptography could well be the first application of quantum mechanics at single-quantum level. The rapid progress in both theory and experiment recent years is reviewed, with emphasis on open questions technological issues.
A Franson-type test of Bell inequalities by photons 10.9 km apart is presented. Energy-time entangled photon-pairs are measured using two-channel analyzers, leading to a violation the 16 standard deviations without subtracting accidental coincidences. Subtracting them, 2-photon interference visibility 95.5% observed, demonstrating that distances up 10 have no significant effect on entanglement. This sets quantum cryptography with photon pairs as practical competitor schemes based weak pulses.
In this paper, we present the quantum key distribution (QKD) network designed and implemented by European project SEcure COmmunication based on Quantum Cryptography (SECOQC) (2004–2008), unifying efforts of 41 research industrial organizations. The paper summarizes SECOQC approach to QKD networks with a focus trusted repeater paradigm. It discusses architecture functionality prototype, which has been put into operation in Vienna 2008 publicly demonstrated framework conference held from...
A pulsed source of energy-time entangled photon pairs pumped by a standard laser diode is proposed and demonstrated. The basic states can be distinguished their time arrival. This greatly simplifies the realization 2-photon quantum cryptography, Bell state analyzers, teleportation, dense coding, entanglement swapping, GHZ-states sources, etc. Moreover well protected during propagation in telecom optical fibers, opening door to few-photon applications communication over long distances.
We present a quantum key distribution system with 2.5 GHz repetition rate using three-state time-bin protocol combined one-decoy approach. Taking advantage of superconducting single-photon detectors optimized for and ultralow-loss fiber, we can distribute secret keys at maximum distance 421 km obtain rates 6.5 bps over 405 km.Received 10 July 2018DOI:https://doi.org/10.1103/PhysRevLett.121.190502© 2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasOptical information...
We present a setup for quantum cryptography based on photon pairs in energy-time Bell states and show its feasibility laboratory experiment. Our scheme combines the advantages of using instead faint laser pulses possibility to preserve entanglement over long distances. Moreover, four-dimensional states, no fast random change bases is required our setup: Nature itself decides whether measure energy or time base, thus rendering eavesdropper attacks "photon number splitting" less efficient.
We propose a quantum repeater protocol which builds on the well-known Duan-Lukin-Cirac-Zoller (DLCZ) [L. M. Duan, D. Lukin, J. I. Cirac, and P. Zoller, Nature (London) 414, 413 (2001)], but uses photon pair sources in combination with memories that allow to store large number of temporal modes. suggest realize such multimode based principle echo, using solids doped rare-earth-metal ions. The use promises speedup entanglement generation by several orders magnitude significant reduction...
General Trojan horse attacks on quantum key distribution systems are analyzed. We illustrate the power of such with today's technology and conclude that all system must implement active counter-measures. In particular include an auxiliary detector monitors any incoming light. show counter-measures can be efficient, provided enough additional privacy amplification is applied to data. present a practical way reduce maximal information gain adversary using attacks. This does security analysis...
We present a fibre-optical quantum key distribution system. It works at 1550 nm and is based on the plug&play set-up. tested stability under field conditions using aerial terrestrial cables performed exchange over 67 km between Geneva Lausanne.
We present a setup for quantum secret sharing based on energy-time entanglement. In opposition to known implementations using three particle Greenberger-Horne-Zeilinger (GHZ) states, our idea takes advantage of only two entangled photons created via parametric down conversion. However, the system comprising pump plus down-converted bare same correlation and can be used mimic qubits. The relatively high coincidence count rates found in enable first time an application communication protocol more than
Single-photon detectors (SPDs) are the most sensitive instruments for light detection. In near-infrared range, SPDs based on III–V compound semiconductor avalanche photodiodes have been extensively used during past two decades diverse applications due to their advantages in practicality including small size, low cost and easy operation. decade, rapid developments increasing demands quantum information science served as key drivers improve device performance of single-photon diodes invent new...
Due to its ability tolerate high channel loss, decoy-state quantum key distribution (QKD) has been one of the main focuses within QKD community. Notably, several experimental groups have demonstrated that it is secure and feasible under real-world conditions. Crucially, however, security feasibility claims made by most these experiments were obtained assumption eavesdropper restricted particular types attacks or finite-key effects are neglected. Unfortunately, such assumptions not possible...
In this paper, we report on the performance of SwissQuantum quantum key distribution (QKD) network. The network was installed in Geneva metropolitan area and run for more than one a half years, from end March 2009 to beginning January 2011. main goal experiment test reliability layer over long period time production environment. A management has been developed manage between three nodes This QKD-secure used by end-users through an application layer.
We present a fully automated quantum key distribution prototype running at 625 MHz clock rate. Taking advantage of ultra low loss fibres and low-noise superconducting detectors, we can distribute 6,000 secret bits per second over 100 km 15 250km.
We perform quantum key distribution (QKD) over a single fibre in the presence of four classical channels C-band dense wavelength division multiplexing (DWDM) configuration using commercial QKD system. The are used for distillation and 1 Gbps encrypted communication, rendering entire system independent any other communication channel than dedicated fibre. successfully distil secret keys spans up to 50 km. separation between at 1551.72 nm nearest is only 200 GHz, while all separated by 100...
Quantum key distribution has emerged as the most viable scheme to guarantee information security in presence of large-scale quantum computers and, thanks continuous progress made past 20 years, it is now commercially available. However, secret rates remain limited just over 10 Mbps due several bottlenecks on receiver side. Here we present a custom multipixel superconducting nanowire single-photon detector that designed high count and precise timing discrimination. Leveraging performance...
A new kind of correlated photon-pair source based on a waveguide integrated periodically poled lithium niobate substrate is reported. Using pump laser few µW at 657 nm, photon-pairs are generated/degenerated 1314 nm. Detecting ~1500 coincidences per second, conversion rate 10-6 pairs photon can be inferred, which four orders magnitude higher than that obtained with previous bulk sources. These results very promising for the realisation sources quantum communication and metrology experiments...
We report experimental distribution of time-bin entangled qubits over 50 km optical fibers. Using actively stabilized preparation and measurement devices we demonstrate violation the CHSH Bell inequality by more than 15 standard deviations without removing detector noise. In addition a proof principle experiment quantum key fibers using photon.
We present a time-multiplexed interferometer based on Faraday mirrors, and apply it to quantum key distribution. The interfering pulses follow exactly the same spatial path, ensuring very high stability self balancing. use of mirrors compensates automatically any birefringence effects polarization dependent losses in transmitting fiber. First experimental results show fringe visibility 0.9984 for 23-km-long interferometer, installed telecom fibers.
A physical random number generator based on the intrinsic randomness of quantum mechanics is described. The events are realized by choice single photons between two outputs a beamsplitter. We present simple device, which minimizes impact photon counters' noise, dead-time and after pulses.
We create pairs of non-degenerate time-bin entangled photons at telecom wavelengths with ultra-short pump pulses. Entanglement is shown by performing Bell kind tests the Franson type visibilities up to 91%. As entanglement can easily be protected from decoherence as encountered in optical fibers, this experiment opens road for complex quantum communication protocols over long distances. also investigate creation more than one photon pair a laser pulse and present simple tool quantify...