A5088898641- Quantum Information and Cryptography
- Quantum Mechanics and Applications
- Photonic and Optical Devices
- Quantum Computing Algorithms and Architecture
- Molecular Communication and Nanonetworks
- Cold Atom Physics and Bose-Einstein Condensates
- Mechanical and Optical Resonators
- Orbital Angular Momentum in Optics
- Neural Networks and Reservoir Computing
- Quantum optics and atomic interactions
- Advanced Optical Sensing Technologies
- Chaos-based Image/Signal Encryption
- Laser-Matter Interactions and Applications
- Random lasers and scattering media
- Space Science and Extraterrestrial Life
- Advanced Measurement and Metrology Techniques
- Advanced MEMS and NEMS Technologies
- Polynomial and algebraic computation
- Optical Wireless Communication Technologies
- CCD and CMOS Imaging Sensors
- Cryptographic Implementations and Security
- Advanced Fiber Optic Sensors
- Opportunistic and Delay-Tolerant Networks
- Scientific Measurement and Uncertainty Evaluation
- Cryptography and Data Security
FHNW University of Applied Sciences and Arts
2015-2022
HES-SO University of Applied Sciences and Arts Western Switzerland
2016
Kantonsschule Schaffhausen
2014-2015
Duke University
2013
Louisiana State University
2006-2010
National Institute of Standards and Technology
2009
Optica
2009
Joint Quantum Institute
2009
University of Maryland, College Park
2009
Folkwang University of the Arts
2003
We propose a class of path-entangled photon Fock states for robust quantum optical metrology, imaging, and sensing in the presence loss. model propagation loss with beam splitters derive reduced density-matrix formalism from which we examine how affects coherence. It is shown that particular entangled number states, contain special superposition photons both arms Mach-Zehnder interferometer, are resilient to environmental decoherence. demonstrate an order magnitude greater visibility than...
Global quantum networks for secure communication can be realized using large fleets of satellites distributing entangled photon pairs between ground-based nodes. Because the cost a satellite depends on its size, smallest will most cost-effective. This Letter describes miniaturized, polarization entangled, photon-pair source operating board nano-satellite. The violates Bell’s inequality with Clauser–Horne–Shimony–Holt parameter <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
We optimize two-mode entangled number states of light in the presence loss order to maximize extraction available phase information an interferometer. Our approach optimizes over entire input Hilbert space with no constraints, other than fixed total initial photon number. Fisher information, which is equivalent minimizing uncertainty. find that limit zero loss, optimal state maximally path-entangled (so-called N00N) state, for small gradually deviates from N00N and large converges a...
There has been much recent interest in quantum optical interferometry for applications to metrology, subwavelength imaging, and remote sensing such as laser radar (LADAR). For LADAR, atmospheric absorption rapidly degrades any state of light, so that high-photon loss the optimal strategy is transmit coherent states which suffer no worse than Beer law classical attenuation, provides sensitivity at shot-noise limit. We show light coupled with photon-number-resolving detectors can provide a...
We show that nonlocal correlation experiments on the two spatially separated modes of a maximally path-entangled number state may be performed and lead to violation Clauser-Horne Bell inequality for any finite photon N. present also an analytical expression two-mode Wigner function investigate Clauser-Horne-Shimony-Holt such states. test other Bell-type inequalities. Some are violated by constant amount
With photon-number resolving detectors, we show compression of interference fringes with increasing photon numbers for a Fabry-Perot interferometer. This feature provides higher precision in determining the position maxima compared to classical detection strategy. We also theoretically supersensitivity if N-photon states are sent into interferometer and measurement is performed.
We report the successful test flight of a device for generating and monitoring correlated photon pairs under near-space conditions up to 35.5 km altitude. Data from ground based qualification tests high altitude experiment demonstrate that continues operate even harsh environmental conditions. The design rugged, compact power-efficient pair system is presented. This enables autonomous systems be deployed on low-resource platforms such as nanosatellites hosting remote nodes quantum key...
We determine the shared information that can be extracted from time-bin entangled photons using frame encoding. consider generated by a general down-conversion source and also model losses, dark counts effects of multiple within each frame. Furthermore, we describe procedure for including other imperfections such as after-pulsing, detector dead-times jitter. The results are illustrated deriving analytic expressions maximum high-dimensional spontaneous parametric down conversion. A key...
We describe a mathematical solution for the generation of entangled N-photon states in two field modes. A simple and compact is presented two-mode Jaynes-Cummings model by combining modes way that only one resulting quasi-modes enters interaction term. The formalism developed then applied to calculate various probabilities analytically. show entanglement, starting from an initial atom defined state may be obtained single step. also entanglement built up case empty cavity excited atoms whose...
We experimentally map the transverse profile of diffraction-limited beams using photon-number-resolving detectors. observe strong compression diffracted beam profiles for high detected photon number. This effect leads to higher contrast than a conventional irradiance between two Airy disk-beams separated by Rayleigh criterion.
We describe our progress on achieving quantum key distribution with high photon efficiency and rate using hyperentanglement. Methods of securing time-bin states classical error correction appropriate for high-dimension protocols will be discussed.
We investigate the violation of Bell-type inequalities for two-qubit Werner-like states parametrized by positive parameter $0\ensuremath{\leqslant}p\ensuremath{\leqslant}1$. use an unbalanced homodyne detection scheme to obtain quantum mechanical probabilities. A Bell-Wigner and Janssens is obtained a large range $p$. The given these greater than one Clauser-Horne inequality. in which attained actually coincides with where are known be nonseparable, i.e., $p>1∕3$. However, improvement...
In this paper we examine the $N$-photon absorption properties of maximally path-entangled number states ($N00N$ states). We consider two cases. The first involves ideal $N00N$ state, one that does not include spectral information. study how probability state scales with $N$, confirming results presented by others in a previous different method. compare to various other states. second case is two-photon for an $N=2$ generated from type-II spontaneous down-conversion event. situation find both...
We present a software based control system for Geiger-mode avalanche photodiodes (GM-APDs) that enables constant photon detection efficiency irrespective of the diode's junction temperature. Furthermore, we demonstrate this passively quenched GM-APDs to double rate events before saturation compared standard method fixes temperature and applied bias voltage. data demonstrating robustness GM-APD when tested in near-space conditions using correlated pair source carried by weather balloon an...
We describe our progress on achieving quantum key distribution with high photon efficiency and rate using hyperentanglement. Methods of securing time-bin states classical error correction appropriate for high-dimension protocols will be discussed.
Abstract Quantum random number generators find applications in both quantum and classical communications schemes, particularly security protocols where they can be used as a source of seed or key material. In this work, we describe the implementation generator on-board nanosatellite deployed low Earth orbit. Our samples shot noise from an entangled photon-pair based on spontaneous parametric down-conversion, linking entropy output to quantization down-converted beam. We present analyzed data...
Modular reduction is a crucial operation in many post-quantum cryptographic schemes, including the Kyber key exchange method or Dilithium signature scheme. However, it can be computationally expensive and pose performance bottleneck hardware implementations. To address this issue, we propose novel approach for computing modular efficiently arbitrary static moduli. Unlike other commonly used methods such as Barrett Montgomery reduction, does not require any multiplications. It dependent on...
We demonstrate a quantum random number generator based on entangled photon-pair statistics on-board CubeSat orbiting in Low Earth Orbit.
Quantum key distribution is a cryptographic primitive for the of symmetric encryption keys between two parties that possess pre-shared secret. Since secret requirement, quantum may be viewed as growing protocol. We note use secrets coupled with access to randomness beacons enable which, though not secure from an information-theoretic standpoint, remains safe.
Polarization entangled photon-pairs are generated and detected onboard a 3U CubeSat in low-Earth orbit that violate Bell’s inequality with CHSH parameter of 2.60 ± 0.06. These results pave the way for space-based quantum networks.
We report the successful test flight of a device for generating and monitoring correlated photon pairs under near-space conditions up to 35.5km altitude. Data from ground based qualification tests high altitude experiment demonstrate that continues operate even harsh environmental conditions. The design rugged, compact power-efficient pair system is presented. This enables autonomous systems be deployed on low-resource platforms such as nanosatellites hosting remote nodes quantum key...