A5037442375- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Satellite Communication Systems
- Optical Wireless Communication Technologies
- Neural Networks and Reservoir Computing
- Quantum-Dot Cellular Automata
- Orbital Angular Momentum in Optics
- Quantum and electron transport phenomena
- Matrix Theory and Algorithms
- Quantum optics and atomic interactions
- ICT Impact and Policies
- Space Satellite Systems and Control
- Advanced Frequency and Time Standards
- Semiconductor Lasers and Optical Devices
- Advanced Optical Sensing Technologies
- Quantum chaos and dynamical systems
- Ion-surface interactions and analysis
- Topology Optimization in Engineering
- Impact of Light on Environment and Health
- Distributed systems and fault tolerance
- Laser and Thermal Forming Techniques
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Optical Network Technologies
- Optical Network Technologies
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2021-2025
University of Basel
2020
Los Alamos National Laboratory
2019
Universität Innsbruck
2016-2018
Scuola Normale Superiore
2015
We present two quantum algorithms based on evolution randomization, a simple variant of adiabatic computing, to prepare state $|x⟩$ that is proportional the solution system linear equations $A\stackrel{\ensuremath{\rightarrow}}{x}=\stackrel{\ensuremath{\rightarrow}}{b}$. The time complexities our are $O\mathbf{(}{\ensuremath{\kappa}}^{2}\mathrm{log}(\ensuremath{\kappa})/\ensuremath{\epsilon}\mathbf{)}$ and...
Quantum metrology offers a quadratic advantage over classical approaches to parameter estimation problems by utilising entanglement and nonclassicality. However, the hurdle of actually implementing necessary quantum probe states measurements, which vary drastically for different metrological scenarios, is usually not taken into account. We show that wide range tasks in metrology, 2D cluster (a particular family useful measurement-based computation) can serve as flexible resources allow one...
ABSTRACT Quantum key distribution (QKD) allows the generation of cryptographic keys beyond computational hardness paradigm and is befitting for secure data transmission requiring long‐term security. The communication distance fiber‐based QKD, however, limited to a few hundred kilometers due exponential scaling signal attenuation. Satellite QKD (SatQKD) can instead leverage free‐space optical links establish long‐range connections enable global‐scale QKD. In this work, we review manifold...
Primary goal of the AEḡIS experiment is to precisely measure free fall antihydrogen within Earth’s gravitational field. To this end, cold (≈50 K) will traverse a two-grid moiré deflectometer before annihilating onto position-sensitive detector, which shall determine vertical position annihilation vertex relative grids with micrometric accuracy. Here, we introduce vertexing detector based on modified mobile camera sensor and experimentally demonstrate that it can antiproton annihilations...
In the context of measurement-based quantum computation a way maintaining coherence graph state is to measure its stabilizer operators. Aside from performing error correction, it possible exploit information gained these measurements characterize and then counteract coherent source errors; that is, determine all parameters an channel applies fixed - but unknown unitary operation physical qubits. Such generated, e.g., by local stray fields act on We study case in which each qubit given may...
Several notions of code products are known in quantum error correction, such as hypergraph products, homological lifted balanced to name a few. In this paper we introduce new product construction which is natural generalization classical codes codes: starting from set component Calderbank-Shor-Steane (CSS) codes, larger CSS obtained where both <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>X</mml:mi></mml:math> parity checks and...
Device-independent certifications employ Bell tests to guarantee the proper functioning of an apparatus from sole knowledge observed measurement statistics, i.e. without assumptions on internal devices. When these are implemented with devices having too low efficiency, one has post-select events that lead successful detections and thus rely a fair sampling assumption. The question we address in this paper is what remains device-independent certification under sampling. We provide intuitive...
Abstract Global Navigation Satellite Systems (GNSSs), such as GPS and Galileo, provide precise time space coordinates globally constitute part of the critical infrastructure modern society. To reliably operate GNSS, a highly accurate stable system is required, one provided by several independent clocks hosted in Precise Timing Facilities (PTFs) around world. The relative clock offset between PTFs periodically measured to have fallback synchronize GNSS satellite clocks. security integrity...
Markov chain methods are remarkably successful in computational physics, machine learning, and combinatorial optimization. The cost of such often reduces to the mixing time, i.e., time required reach steady state chain, which scales as<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow class="MJX-TeXAtom-ORD"><mml:mo>δ</mml:mo></mml:mrow><mml:mrow class="MJX-TeXAtom-ORD"><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>, inverse spectral gap. It...
The problem of Hamiltonian purification introduced by Burgarth et al. [D. K. al., Nat. Commun. 5, 5173 (2014)] is formalized and discussed. Specifically, given a set non-commuting Hamiltonians {h1, . ., hm} operating on d-dimensional quantum system Hd, the consists in identifying commuting {H1,...,Hm} larger dE-dimensional H_{dE} which embeds H_d as proper subspace, such that hj = PHjP with P being projection allows one to recover Hd from HdE notions spanning-set generator an algebra are...
A quantum state can be characterized from the violation of a Bell inequality. The well-known CHSH inequality for example used to quantify fidelity (up local isometries) measured with respect singlet state. In this work, we look minimum leading non-trivial fidelity. particular, provide new analytical approach explore problem in device-independent framework, where bound holds without assumption about internal working devices test. We give an which pushes threshold from<mml:math...
Quantum algorithms for solving the Linear System (QLS) problem are among most investigated quantum of recent times, with potential applications including solution computationally intractable differential equations and speed-ups in machine learning. A fundamental parameter governing efficiency QLS solvers is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>κ</mml:mi></mml:math>, condition number coefficient matrix...
Satellite miniaturization and sinking costs of manu-facturing launches are bringing Moon missions in the focus many space companies agencies. However, achieving desired data rates on CubeSats over long ranges is proving increasingly challenging with traditional radio-frequency communication systems. Free-space optical (FSO) communications offer a compact, light, low-power alternative higher throughput fewer limitations (e.g., governmental regulations, channel interference, eavesdropping...)....
Satellite based quantum key distribution (QKD) enables the delivery of keys for secure communications over long distances. Maturity technology as well industrial interest keep increasing. So does readiness satellite free-space optical communications. A QKD system comprises a communication subsystem and classical (public channel). Both are implemented with optics. Thus, in design, there strong synergies that should be exploited much possible lead to an all-optical system. In this paper, we...
Different pointing errors from different sources cause an angular deviation in the uplink beam transmitted optical ground station (OGS) to a satellite. In link-budget calculations, intensity loss due errors, "pointing loss", is usually given constant value regardless of satellite elevation. this paper, elevation-dependent losses are calculated, considering with Gaussian profile. The elevation and divergence considered assess impact following tracking errors: OGS static misalignment,...
Several notions of code products are known in quantum error correction, such as hyper-graph products, homological lifted balanced to name a few. In this paper we introduce new product construction which is natural generalisation classical codes codes: starting from set component Calderbank-Shor-Steane (CSS) codes, larger CSS obtained where both $X$ parity checks and $Z$ associated codes. We deduce several properties the including bounds on distance, show that built-in redundancies result...
The use of quantum key distribution (QKD) to improve security may impact the quality service (Qos) high rate classical data links. generation process with an empty buffer can be modeled as a queuing system, and throughput limits determined using queueing theory assess on QoS. proposed model is based on-demand paradigm. Based results this study, discrete variable (DV)-QKD-secured link could designed bounds guarantee given Furthermore, we validate derived by comparing theoretical derivations...
Quantum key distribution (QKD) enables secure communication even in presence of quantum computers. Satellite based systems enable worldwide and connection terrestrial networks. In future, QKD satellite constellations can be operated to service ground users that are connected using an optical station. These stations assumed deployed two scenarios. One is the option as end-user station, which user directly via The other use a provider intermediary fiber line. performance link depends on,...
The use of free-space optical (FSO) links has the potential to significantly increase data transmission rates compared radio and they enable possibility performing quantum communication. For development FSO components, including transmitters receivers, novel communications protocols, it is essential have ability comprehensively test performance across several different communication scenarios – e.g., aircraft-to-ground, aircraft-to-aircraft, satellite-to-ground, ground-to-satellite. To this...
Free-Space Optical (FSO) communication is a technology that enables ultra-high-rate data exchange and will be crucial in enabling secure Quantum Key Distribution (QKD) over long distances. However, FSO systems are comparatively complex technologies, comprising variety of subsystems all have to work together coordinated way. Hence, assessing the feasibility establishing (classical or quantum) link given scenario difficult task itself. Here we introduce QCalc, software tool aims at easing...
Quantum key distribution (QKD) enables private communication with information theoretic security. Free-space optical allows one to implement QKD without the limitations imposed by fiber networks such as exponential scaling of transmission losses in fibers. Therefore, free-space via satellite links is a promising technology provide long-distance quantum connections. In systems, background light main source noise, which has be suppressed means spectral, spatial, and temporal filtering reach...
Quantum key distribution (QKD) allows the generation of cryptographic keys beyond computational hardness paradigm and is befitting for secure data transmission requiring long-term security. The communication distance fibre-based QKD, however, limited to a few hundred kilometers due exponential scaling signal attenuation. Satellite QKD (SatQKD) can instead leverage free-space optical links establish long-range connections enable global-scale QKD. In this work we review manifold design choices...
The primary goal of the AEgIS experiment is to precisely measure free fall antihydrogen within Earth's gravitational field. To this end, a cold ~50K beam has pass through two grids forming moir\'e deflectometer before annihilating onto position-sensitive detector, which shall determine vertical position annihilation vertex relative with micrometric accuracy. Here we introduce vertexing detector based on modified mobile camera sensor and experimentally demonstrate that it can antiproton...