scholarly journals Optimal strategy to certify quantum nonlocality

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Gómez ◽  
D. Uzcátegui ◽  
I. Machuca ◽  
E. S. Gómez ◽  
S. P. Walborn ◽  
...  
Keyword(s):  
Experimental Data ◽  
Random Number ◽  
Bell Inequality ◽  
Random Number Generation ◽  
Quantum Nonlocality ◽  
Entangled Photons ◽  
Challenging Problem ◽  
Practical Applications ◽  
Variable Limit ◽  
The One

AbstractCertification of quantum nonlocality plays a central role in practical applications like device-independent quantum cryptography and random number generation protocols. These applications entail the challenging problem of certifying quantum nonlocality, something that is hard to achieve when the target quantum state is only weakly entangled, or when the source of errors is high, e.g. when photons propagate through the atmosphere or a long optical fiber. Here we introduce a technique to find a Bell inequality with the largest possible gap between the quantum prediction and the classical local hidden variable limit for a given set of measurement frequencies. Our method represents an efficient strategy to certify quantum nonlocal correlations from experimental data without requiring extra measurements, in the sense that there is no Bell inequality with a larger gap than the one provided. Furthermore, we also reduce the photodetector efficiency required to close the detection loophole. We illustrate our technique by improving the detection of quantum nonlocality from experimental data obtained with weakly entangled photons.

scholarly journals Optimal Strategy to Certify Quantum Nonlocality

2021 ◽  
Author(s):  
S. Gómez ◽  
D. Uzcátegui ◽  
I. Machuca ◽  
E. S. Gómez ◽  
S. P. Walborn ◽  
...  
Keyword(s):  
Experimental Data ◽  
Random Number ◽  
Bell Inequality ◽  
Random Number Generation ◽  
Quantum Nonlocality ◽  
Entangled Photons ◽  
Challenging Problem ◽  
Practical Applications ◽  
Variable Limit ◽  
The One

Abstract Certification of quantum nonlocality plays a central role in practical applications like device-independent quantum cryptography and random number generation protocols. These applications entail the challenging problem of certifying quantum nonlocality, something that is hard to achieve when the target quantum state is only weakly entangled, or when the source of errors is high, e.g. when photons propagate through the atmosphere or a long optical fiber. Here we introduce a technique to find a Bell inequality with the largest possible gap between the quantum prediction and the classical local hidden variable limit for a given set of measurement frequencies. Our method represent an efficient strategy to certify quantum nonlocal correlations from experimental data without requiring extra measurements, in the sense that there is no Bell inequality with a larger gap than the one provided. Furthermore, we also reduce the photodetector efficiency required to close the detection loophole. We illustrate our technique by improving the detection of quantum nonlocality from experimental data obtained with weakly entangled photons.

scholarly journals Mutually unbiased bases and symmetric informationally complete measurements in Bell experiments

2021 ◽  
Vol 7 (7) ◽  
pp. eabc3847
Author(s):  
Armin Tavakoli ◽  
Máté Farkas ◽  
Denis Rosset ◽  
Jean-Daniel Bancal ◽  
Jedrzej Kaniewski
Keyword(s):  
Quantum Key Distribution ◽  
Random Number ◽  
Random Number Generation ◽  
Bell Inequalities ◽  
Extremal Point ◽  
Optimal Rate ◽  
Quantum Nonlocality ◽  
Space Structures ◽  
Mutually Unbiased Bases ◽  
Practical Relevance

Mutually unbiased bases (MUBs) and symmetric informationally complete projectors (SICs) are crucial to many conceptual and practical aspects of quantum theory. Here, we develop their role in quantum nonlocality by (i) introducing families of Bell inequalities that are maximally violated by d-dimensional MUBs and SICs, respectively, (ii) proving device-independent certification of natural operational notions of MUBs and SICs, and (iii) using MUBs and SICs to develop optimal-rate and nearly optimal-rate protocols for device-independent quantum key distribution and device-independent quantum random number generation, respectively. Moreover, we also present the first example of an extremal point of the quantum set of correlations that admits physically inequivalent quantum realizations. Our results elaborately demonstrate the foundational and practical relevance of the two most important discrete Hilbert space structures to the field of quantum nonlocality.

scholarly journals A Novel Random Number Generator Based on Fractional Order Chaotic Chua System

2020 ◽  
Vol 26 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Fatih Ozkaynak
Keyword(s):  
Fractional Order ◽  
Discrete Time ◽  
Continuous Time ◽  
Chaotic Systems ◽  
Random Number ◽  
Random Number Generator ◽  
Number Generator ◽  
Practical Applications ◽  
The One ◽  
Time Systems

One of the practical applications of chaotic systems is the design of a random number generator. In the literature, generally random number generators are designed using discrete time chaotic systems. The reason for the use of the discrete time chaotic systems in the design architecture is that the latter have a simpler structure than the continuous time chaotic systems. In order to observe chaos in continuous time systems, the system must have at least three degrees. It is shown that for fractional order chaotic systems chaos can be observed even in a lower system degree. The aim of this study is to develop a random number generator using a fractional order chaotic Chua system. The proposed generator is analysed using various randomness tests. The analysis results show that the proposed generator passes the random requirements successfully. On the one hand, this study is important because it demonstrates the practical application of fractional order chaotic systems. On the other hand, it provides an alternative to designs based on discrete time chaotic systems.

UNBIASED QUANTUM RANDOM NUMBER GENERATION BASED ON SQUEEZED VACUUM STATE

2012 ◽  
Vol 10 (01) ◽  
pp. 1250012 ◽  
Author(s):  
YANYANG ZHU ◽  
GUANGQIANG HE ◽  
GUIHUA ZENG
Keyword(s):  
Random Number ◽  
Quantum Noise ◽  
Random Number Generation ◽  
Vacuum State ◽  
Random Numbers ◽  
Squeezed Vacuum State ◽  
Quantum Randomness ◽  
Number Generation ◽  
Squeezed Vacuum ◽  
The One

In this paper, a new quantum random number generation scheme which is implemented by measuring quantum noise of the squeezed vacuum state is proposed. In the proposed scheme, the Shannon entropy is employed to measure randomness of the generated random numbers. In addition, some characteristics of the generated random numbers are investigated. To reach the pure quantum randomness, an extraction approach based on universal hash functions for the generated quantum random numbers is presented. Results show that the proposed scheme based on squeezed vacuum state has remarkable advantages over the one associated with the vacuum state.

ISOTHERMAL MOLECULAR DYNAMICS: A PRACTICAL STUDY

1993 ◽  
Vol 04 (03) ◽  
pp. 539-551
Author(s):  
JEAN-LUC FATTEBERT ◽  
ERNESTO BONOMI
Keyword(s):  
Molecular Dynamics ◽  
Random Number ◽  
Canonical Ensemble ◽  
Random Number Generation ◽  
Dynamics Simulation ◽  
Time Intervals ◽  
One Dimensional ◽  
Long Time ◽  
Particle Velocities ◽  
The One

In a molecular dynamics simulation, trapping of the phase space trajectory can occur at low energy for long time intervals. To untrap that evolution and recover the canonical ensemble description, at regular clock hits, all particle velocities are randomly redistributed according to the Maxwell statistics. The organization of this hybrid evolution mixing molecular dynamics and random number generation leads to a fully parallel and synchronous algorithm. An illustration of this approach on the one-dimensional jellium is presented. For large values of the coupling λ for which the evolution at constant energy is trapped, the hybrid method allows to reproduce the exact Boltzmann statistical description. Computer simulations show that the Nosé-Hoover method does not really improve the pure molecular dynamics for the one dimensional jellium.

Digital-Analog Hybrid Scheme and Its Application to Chaotic Random Number Generators

2017 ◽  
Vol 27 (14) ◽  
pp. 1750210 ◽  
Author(s):  
Zeshi Yuan ◽  
Hongtao Li ◽  
Yunchi Miao ◽  
Wen Hu ◽  
Xiaohua Zhu
Keyword(s):  
Graphics Processing Units ◽  
Random Number ◽  
Random Number Generator ◽  
Random Number Generation ◽  
Main Body ◽  
Hybrid Scheme ◽  
Memory Element ◽  
Finite Precision ◽  
Practical Applications ◽  
Field Programmable

Practical random number generation (RNG) circuits are typically achieved with analog devices or digital approaches. Digital-based techniques, which use field programmable gate array (FPGA) and graphics processing units (GPU) etc. usually have better performances than analog methods as they are programmable, efficient and robust. However, digital realizations suffer from the effect of finite precision. Accordingly, the generated random numbers (RNs) are actually periodic instead of being real random. To tackle this limitation, in this paper we propose a novel digital-analog hybrid scheme that employs the digital unit as the main body, and minimum analog devices to generate physical RNs. Moreover, the possibility of realizing the proposed scheme with only one memory element is discussed. Without loss of generality, we use the capacitor and the memristor along with FPGA to construct the proposed hybrid system, and a chaotic true random number generator (TRNG) circuit is realized, producing physical RNs at a throughput of Gbit/s scale. These RNs successfully pass all the tests in the NIST SP800-22 package, confirming the significance of the scheme in practical applications. In addition, the use of this new scheme is not restricted to RNGs, and it also provides a strategy to solve the effect of finite precision in other digital systems.

Random Number Generation Based on the Rossler Attractor

2014 ◽  
Vol 1 ◽  
pp. 272-275 ◽  
Author(s):  
Vincent Canals ◽  
Antoni Morro ◽  
Josep L. Rosselló
Keyword(s):  
Random Number ◽  
Random Number Generation ◽  
Number Generation

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

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