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A Detailed Analysis of Secrecy and Performance Metrics in Hybrid RF/ FSO Communication Systems: Implications of Composite Weibull and Log-normal Fading with M Turbulent Channels

A Detailed Analysis of Secrecy and Performance Metrics in Hy...

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Intelligent Signal Processing and Effective Communication Technologies (INSPECT), IEEE International Conference on

作者： Deepak Upadhyay Kunj Bihari Sharma Mridul Gupta Abhay Upadhyay Nookala Venu Dept. of Computer Science and Engineering Graphic Era Hill University Dehradun India Dept. of Computer Science and Engineering Graphic Era deemed to be University Dehradun India Data Science and Quantum Computing ABV Indian Institute of Information Technology and Management Gwalior India

ISBN: (数字)9798350379525

ISBN: (纸本)9798350379532

In this paper, we have analyzed the secrecy performance and system operation performance for hybrid RF/FSO systems against composite Weibull-log-normal fading channel with M turbulent channels. The performance is evaluated by carrying out extensive simulations to calculate Signal-to-Noise Ratio (SNR), Bit Error Rate (BER) and outage probability, we also re-evaluate channel capacity and secrecy capacity with respect of environmental conditions. Compared with RF only system, FSO only standalone scheme and some meaningful orthogonal-modulation multicarrier IM/DD-based schemes proposed by the literatures. Similarly, the utilization of adaptive modulation schemes improved resistance to fading and roughness in systems. The above results confirm the hybridization of both RF and FSO a comprehensive solution for dependable communication in different and even hostile surrounding conditions which set this work as reliable foundation point towards forthcoming research activity or application relevance within all range telecommunication sector.

关键词： Fading channels Radio frequency Communication systems Systems operation Simulation Bit error rate Modulation Probability Power system reliability Signal to noise ratio

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Shallow quantum circuits for efficient preparation of Slater determinants and correlated states on a quantum computer

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Physical Review A 2023年第2期108卷 022416-022416页

作者： Chong Hian Chee Daniel Leykam Adrian M. Mak Dimitris G. Angelakis Centre for Quantum Technologies National University of Singapore 3 Science Drive 2 Singapore 117543 Institute of High Performance Computing Agency for Science Technology & Research (A*STAR) 1 Fusionopolis Way 16-16 Connexis Singapore 138632 School of Electrical and Computer Engineering Technical University of Crete 73100 Chania Greece AngelQ Quantum Computing 531A Upper Cross Street 04-95 Hong Lim Complex Singapore 051531

Fermionic Ansatz state preparation is a critical subroutine in many quantum algorithms such as the variational quantum eigensolver for quantum chemistry and condensed-matter applications. The shallowest circuit depth needed to prepare Slater determinants and correlated states to date scales at least linearly with respect to the system size N. Inspired by data-loading circuits developed for quantum machine learning, we propose an alternate paradigm that provides shallower, yet scalable, O(dlog22N) two-qubit gate-depth circuits to prepare such states with d fermions, offering a subexponential reduction in N over existing approaches in second quantization, enabling high-accuracy studies of d≪O(N/log22N) fermionic systems with larger basis sets on near-term quantum devices.

关键词： quantum algorithms for chemical calculations

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A quantum Photonic Chip for Binary Classification

A Quantum Photonic Chip for Binary Classification

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Conference on Lasers and Electro-Optics (CLEO)

作者： H. X. Lin H. Zhang H. Cai P. Griffin A. Q. Liu Quantum Science and Engineering Centre (QSec) Nanyang Technological University Singapore Institute of Microelectronics A*STAR (Agency for Science Technology and Research) Singapore School of Computing and Information Systems Singapore Management University Singapore

ISBN: (纸本)9781957171258

On the silicon photonic chip, we apply Mach Zehnder Interferometer (MZI) and optical network to manipulate the phase difference and amplitude distribution of the input light. The two or three-dimensional input data is encoded in the light amplitude distribution and the genetic algorithm is applied to update the angle parameters of the MZIs to improve the classification result.

关键词： Genetic algorithms Mach Zehnder interferometers Optical networks quantum computing Silicon

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One-Shot Point-to-Point Channel Simulation

One-Shot Point-to-Point Channel Simulation

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IEEE International Symposium on Information Theory

作者： Michael X. Cao Navneeth Ramakrishnan Mario Berta Marco Tomamichel Department of Electrical and Computer Engineering National University of Singapore Singapore Centre for Quantum Technologies National University of Singapore Singapore Department of Computing Imperial College London London UK Institute for Quantum Information and Matter California Institute of Technology Pasadena USA AWS Center for Quantum Computing Pasadena USA

ISBN: (数字)9781665421591

ISBN: (纸本)9781665421607

We study the problem of one-shot channel simulation of DMCs with unlimited shared randomness. For any fixed tolerance measured in total variational distance, we propose an achievability bound and a converse bound on the size of the code to simulate the channel. The achievability bound utilizes the convex split lemma, whereas the converse bound is the result of the relationships between smoothed max-divergences and the max-mutual information. The achievability proof does not rely on a "universal state" (compared with some previous related works), and provides a tighter bound. Using the two bounds, we also provide an alternative proof to the reverse Shannon theorem.

关键词： Codes Monte Carlo methods Protocols Size measurement

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Optimized Current Density Reconstruction from Widefield quantum Diamond Magnetic Field Maps

arXiv

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arXiv 2024年

作者： Midha, Siddhant Parashar, Madhur Bathla, Anuj Broadway, David A. Tetienne, Jean-Philippe Saha, Kasturi Department of Electrical Engineering Indian Institute of Technology Bombay Powai Mumbai400076 India Center for Research in Nanotechnology and Science Indian Institute of Technology Bombay Powai Mumbai400076 India School of Science RMIT University MelbourneVIC3001 Australia Center of Excellence in Quantum Information Computing Science and Technology Indian Institute of Technology Bombay Powai Mumbai400076 India Indian Institute of Technology Bombay Powai Mumbai400076 India

quantum Diamond Microscopy using Nitrogen-Vacancy (NV) defects in diamond crystals has enabled the magnetic field imaging of a wide variety of nanoscale current profiles. Intimately linked with the imaging process is the problem of reconstructing the current density, which provides critical insight into the structure under study. This manifests as a non-trivial inverse problem of current reconstruction from noisy data, typically conducted via Fourier-based approaches. Learning algorithms and Bayesian methods have been proposed as novel alternatives for inference-based reconstructions. We study the applicability of Fourier-based and Bayesian methods for reconstructing two-dimensional current density maps from magnetic field images obtained from NV imaging. We discuss extensive numerical simulations to elucidate the performance of the reconstruction algorithms in various parameter regimes, and further validate our analysis via performing reconstructions on experimental data. Finally, we examine parameter regimes that favor specific reconstruction algorithms and provide an empirical approach for selecting regularization in Bayesian methods. © 2024, CC BY.

关键词： Inverse problems

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Intrinsic Dynamic Generation of Spin Polarization by Time-Varying Electric Field

arXiv

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arXiv 2024年

作者： Feng, Xukun Cao, Jin Zhang, Zhi-Fan Ang, Lay Kee Lai, Shen Jiang, Hua Xiao, Cong Yang, Shengyuan A. Singapore University of Technology and Design Singapore487372 Singapore Institute of Applied Physics and Materials Engineering University of Macau China Fudan University Shanghai200433 China Institute for Nanoelectronic Devices and Quantum Computing State Key Laboratory of Surface Physics Fudan University Shanghai200433 China

Electric control of spin in insulators is desired for low-consumption and ultrafast spintronics, but the underlying mechanism remains largely unexplored. Here, we propose an intrinsic effect of dynamic spin generation driven by time-varying electric field. In the intraband response regime, it can be nicely formulated as a Berry curvature effect and leads to two phenomena that are forbidden in the dc limit: linear spin generation in nonmagnetic insulators and intrinsic Néel spin-orbit torque in PT -symmetric antiferromagnetic insulators. These phenomena are driven by the time derivative of field rather than the field itself, and have a quantum origin in the first-order dynamic anomalous spin polarizability. Combined with first-principles calculations, we predict sizable effects driven by terahertz field in nonmagnetic monolayer Bi and in antiferromagnetic even-layer MnBi2Te4, which can be detected in experiment. Copyright © 2024, The Authors. All rights reserved.

关键词： Spin polarization

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Exact entanglement cost of quantum states and channels under positive-partial-transpose-preserving operations

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Physical Review A 2023年第1期107卷 012429-012429页

作者： Xin Wang Mark M. Wilde Institute for Quantum Computing Baidu Research Beijing 100093 China Joint Center for Quantum Information and Computer Science University of Maryland College Park Maryland 20742 USA Hearne Institute for Theoretical Physics Department of Physics and Astronomy Center for Computation and Technology Louisiana State University Baton Rouge Louisiana 70803 USA School of Electrical and Computer Engineering Cornell University Ithaca New York 14850 USA

This paper establishes single-letter formulas for the exact entanglement cost of simulating quantum channels under free quantum operations that completely preserve positivity of the partial transpose (PPT). First, we introduce the κ-entanglement measure for point-to-point quantum channels, based on the idea of the κ entanglement of bipartite states, and we establish several fundamental properties for it, including amortization collapse, monotonicity under PPT superchannels, additivity, normalization, faithfulness, and nonconvexity. Second, we introduce and solve the exact entanglement cost for simulating quantum channels in both the parallel and sequential settings, along with the assistance of free PPT-preserving operations. In particular, we establish that the entanglement cost in both cases is given by the same single-letter formula, the κ-entanglement measure of a quantum channel. We further show that this cost is equal to the largest κ entanglement that can be shared or generated by the sender and receiver of the channel. This formula is calculable by a semidefinite program, thus allowing for an efficiently computable solution for general quantum channels. Noting that the sequential regime is more powerful than the parallel regime, another notable implication of our result is that both regimes have the same power for exact quantum channel simulation, when PPT superchannels are free. For several basic Gaussian quantum channels, we show that the exact entanglement cost is given by the Holevo-Werner formula [Holevo and Werner, Phys. Rev. A 63, 032312 (2001)], giving an operational meaning of the Holevo-Werner quantity for these channels.

关键词： Entanglement manipulation Entanglement measures quantum channels quantum communication quantum entanglement

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Electric-field control of photon indistinguishability in cascaded decays in quantum dots

arXiv

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arXiv 2025年

作者： Undeutsch, Gabriel Aigner, Maximilian Garcia, Ailton J. Reindl, Johannes Peter, Melina Mader, Simon Weidinger, Christian Covre da Silva, Saimon F. Manna, Santanu Schöll, Eva Rastelli, Armando Institute of Semiconductor and Solid State Physics Johannes Kepler University Linz Austria Instituto de Física Gleb Wataghin Universidade Estadual de Campinas Campinas Brazil Department of Electrical Engineering Indian Institute of Technology Delhi India Institute for Integrated Circuits and Quantum Computing Johannes Kepler University Linz Austria

Photon indistinguishability, entanglement, and antibunching are key ingredients in quantum optics and photonics. Decay cascades in quantum emitters offer a simple method to create entangled-photon-pairs with negligible multi-pair generation probability. However, the degree of indistinguishability of the photons emitted in a cascade is intrinsically limited by the lifetime ratio of the involved transitions. Here we show that, for the biexciton-exciton cascade in a quantum dot, this ratio can be widely tuned by an applied electric field. Hong-Ou-Mandel interference measurements of two subsequently emitted biexciton photons show that their indistinguishability increases with increasing field, following the theoretically predicted behavior. At the same time, the emission linewidth stays close to the transform-limit, favoring applications relying on the interference among photons emitted by different sources. Copyright © 2025, The Authors. All rights reserved.

关键词： Semiconductor quantum dots

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Single-Shot Single-Mode Optical Two-Parameter Displacement Estimation beyond Classical Limit

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Physical Review Letters 2023年第23期131卷 230801-230801页

作者： Fumiya Hanamura Warit Asavanant Seigo Kikura Moeto Mishima Shigehito Miki Hirotaka Terai Masahiro Yabuno Fumihiro China Kosuke Fukui Mamoru Endo Akira Furusawa Department of Applied Physics School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Optical Quantum Computing Research Team RIKEN Center for Quantum Computing 2-1 Hirosawa Wako Saitama 351-0198 Japan Advanced ICT Research Institute National Institute of Information and Communications Technology 588-2 Iwaoka Nishi-ku Kobe Hyogo 651-2492 Japan Graduate School of Engineering Kobe University 1-1 Rokkodai-cho Nada-ku Kobe Hyogo 657-0013 Japan

Uncertainty principle prohibits the precise measurement of both components of displacement parameters in phase space. We have theoretically shown that this limit can be beaten using single-photon states, in a single-shot and single-mode setting [F. Hanamura et al., Estimation of gaussian random displacement using non-gaussian states, Phys. Rev. A 104, 062601 (2021).]. In this Letter, we validate this by experimentally beating the classical limit. In optics, this is the first experiment to estimate both parameters of displacement using non-Gaussian states. This result is related to many important applications, such as quantum error correction.

关键词： Optical quantum information processing quantum error correction quantum optics quantum parameter estimation quantum sensing

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Special Session: STT-MRAMs: technology, Design and Test

Special Session: STT-MRAMs: Technology, Design and Test

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VLSI Test Symposium

作者： Anteneh Gebregiorgis Lizhou Wu Christopher Mü nch Siddharth Rao Mehdi B. Tahoori Said Hamdioui Department of Quantum and Computer Engineering Delft University of Technology Delft Netherlands Chair of Dependable Nano Computing Karlsruhe Institute of Technology Karlsruhe Germany IMEC Leuven Belgium

STT-MRAM has long been a promising non-volatile memory solution for the embedded application space owing to its attractive characteristics such as non-volatility, low leakage, high endurance, and scalability. However, the operating requirements for high-performance computing (HPC) and low power (LP) applications involve different challenges. This paper addresses different aspects of STT-MRAM; it will cover state-of-the-art, some new results and future challenges related to technology, design and test. While STT-MRAM devices have shown encouraging performance metrics at device-level, a key challenge has been achieving backend-of-line (BEOL) CMOS compatibility, while retaining the benefits of low power operation. Scaling demands to improve data densities have placed additional challenges in terms of addressing the impact of process-induced damage on device performance at CD < 100 nm. In addition, the paper discusses the design of reliable read mechanism considering the variability effects. Moreover, the failure of traditional fault modeling and test approaches in model STT-MRAM unique defects for appropriate test solutions is demonstrated in this paper based on silicon data.

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