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Quantum-enhanced interferometry with asymmetric beam splitters

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arXiv 2020年

作者： Zhong, Wei Wang, Fan Zhou, Lan Xu, Peng Sheng, Yu-Bo Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing210003 China National Laboratory of Solid State Microstructures Nanjing University Nanjing210093 China School of Science Nanjing University of Posts and Telecommunications Nanjing210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing210003 China

In this paper, we investigate the phase sensitivities in two-path optical interferometry with asymmetric beam splitters. Here, we present the optimal conditions for the transmission ratio and the phase of the beam splitter to gain the highest sensitivities for a general class of non-classical states with parity symmetry. Additionally, we address the controversial question of whether the scheme with a combination of coherent state and photon-added or photon-subtracted squeezed vacuum state is better or worse than the most celebrated one using a combination of coherent state and squeezed vacuum state. Copyright © 2020, The Authors. All rights reserved.

关键词： Fisher information matrix

Thermal effects of the quantum states generated from the isomorphs of PPKTP crystal

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arXiv 2018年

作者： Jin, Rui-Bo Chen, Guo-Qun Laudenbach, Fabian Zhao, Shengmei Lu, Pei-Xiang Laboratory of Optical Information Technology Wuhan Institute of Technology Wuhan430205 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Security & Communication Technologies Center for Digital Safety & Security AIT Austrian Institute of Technology GmbH Donau-City-Str. 1 Vienna1220 Austria Quantum Optics Quantum Nanophysics and Quantum Information Faculty of Physics University of Vienna Boltzmanngasse 5 Vienna1090 Austria

We theoretically and numerically investigate the temperature-dependent properties of the biphotons generated from four isomorphs of periodically poled KTiOPO4 (PPKTP): i.e., PPRTP, PPKTA, PPRTA and PPCTA. It is discovered that the first type of group-velocity-matched (GVM) wavelength is decreased by 6.4, 1.2, 8.9, 25.6 and 6.3 nm, while the phase-matched wavelength is decreased by 4.4, -0.4, -1.2, 29.1 and 59.5 nm for PPKTP, PPRTP, PPKTA, PPRTA and PPCTA, respectively, when the temperature is increased from 20 ◦C to 120 ◦C. Although the maximal spectral purity of the heralded single photons is not changed at different temperature, the Hong-Ou-Mandel (HOM) interference shows different patterns due to a shift of the joint spectral amplitude. These thermal effects are very important for precise control of the quantum state for the future applications in quantum information processing, for example, in quantum interference or spectroscopy. Copyright © 2018, The Authors. All rights reserved.

关键词： Quantum optics

Proposal of a free-space-to-chip pipeline for transporting single atoms

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arXiv 2023年

作者： Liu, Aiping Liu, Jiawei Kang, Zhanfei Chen, Guang-Jie Xu, Xin-Biao Ren, Xifeng Guo, Guang-Can Wang, Qin Zou, Chang-Ling Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing210003 China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei230026 China Broadband Wireless Communication and Sensor Network Technology Key Lab of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China

A free-space-to-chip pipeline is proposed to efficiently transport single atoms from a magneto-optical trap to an on-chip evanescent field trap. Due to the reflection of the dipole laser on the chip surface, the conventional conveyor belt approach can only transport atoms close to the chip surface but with a distance of about one wavelength, which prevents efficient interaction between the atom and the on-chip waveguide devices. Here, based on a two-layer photonic chip architecture, a diffraction beam of the integrated grating with an incident angle of the Brewster angle is utilized to realize free-space-to-chip atom pipeline. Numerical simulation verified that the reflection of the dipole laser is suppressed and that the atoms can be brought to the chip surface with a distance of only 100 nm. Therefore, the pipeline allows a smooth transport of atoms from free space to the evanescent field trap of waveguides and promises a reliable atom source for a hybrid photonic-atom chip. © 2023, CC BY.

关键词： Atoms

Energy-efficient resource allocation for uplink OFDMA systems using correlated equilibrium

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Energy-efficient resource allocation for uplink OFDMA system...

2012 IEEE Global communications Conference (GLOBECOM)

作者： Dan Wu Liang Zhou Yueming Cai Joel Rodrigues Institute of Communications Engineering PLA University of Science and Technology Nanjing China The Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China National Mobile Communications Research Laboratory Southeast University Nanjing China Instituto de Telecomunicaçőes University of Beira Interior Portugal

In this work, we propose a correlated equilibrium (CE)-based energy-efficient resource allocation scheme for uplink OFDMA systems. At first, we construct an energy-efficient resource allocation game, where each subcarrier is viewed as a player to choose the most satisfying user, and the objective is to balance the tradeoff between the total energy efficiency and the fairness. Since the CE can achieve better performance by helping the non-cooperative players coordinate their strategies, we employ the CE to analyze the proposed game. Next, we derive the condition under which the CE is Pareto optimal and employ linear programming duality to show its closed-form expressions. Furthermore, we present a linear programming method and a distributed algorithm based on the regret matching procedure to implement the CE, respectively. Simulation results demonstrate that our scheme is able to achieve good convergence, Pareto optimality, and fairness.

关键词：

Hierarchical Deep Reinforcement Learning for Age-of-Information Minimization in IRS-aided and wireless-powered wireless networks

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arXiv 2022年

作者： Gong, Shimin Cui, Leiyang Gu, Bo Lyu, Bin Hoang, Dinh Thai Niyato, Dusit The School of Intelligent Systems Engineering Sun Yat-sen University Shenzhen518055 China Key Laboratory of Ministry of Education in Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications China The School of Electrical and Data Engineering University of Technology Sydney Australia School of Computer Science and Engineering Nanyang Technological University Singapore

In this paper, we focus on a wireless-powered sensor network coordinated by a multi-antenna access point (AP). Each node can generate sensing information and report the latest information to the AP using the energy harvested from the AP’s signal beamforming. blueWe aim to minimize the average age-of-information (AoI) by adapting the nodes’ transmission scheduling and the transmission control strategies jointly. To reduce the transmission delay, an intelligent reflecting surface (IRS) is used to enhance the channel conditions by controlling the AP’s beamforming bluevector and the IRS’s phase shifting bluematrix. blueConsidering dynamic data arrivals at different sensing nodes, we propose a hierarchical deep reinforcement learning (DRL) framework to bluefor AoI minimization in two steps. The users’ transmission scheduling is firstly determined by the outer-loop DRL approach, e.g. the DQN or PPO algorithm, and then the inner-loop optimization is used to adapt either the uplink information transmission or downlink energy transfer to all nodes. A simple and efficient approximation is also proposed to reduce the blueinner-loop rum time overhead. Numerical results verify that the hierarchical learning framework outperforms typical baselines in terms of the average AoI and proportional fairness among different nodes. © 2022, CC BY.

关键词： Reinforcement learning

Deep Reinforcement Learning for Fresh Data Collection in UAV-assisted IoT networks

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Deep Reinforcement Learning for Fresh Data Collection in UAV...

IEEE Conference on Computer communications Workshops, INFOCOM Wksps

作者： Mengjie Yi Xijun Wang Juan Liu Yan Zhang Bo Bai Science and Technology on Communication Network Laboratory Shijiazhuang Hebei China Key Laboratory of Wireless Sensor Network & Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences 865 Changning Road Shanghai China School of Electrical Engineering and Computer Science Ningbo University Zhejiang China Theory Lab (FKA Future Network Theory Lab) 2012 Labs Huawei Technologies Co. Ltd. Hong Kong

ISBN: (数字)9781728186955

ISBN: (纸本)9781728186962

Due to the flexibility and low operational cost, dispatching unmanned aerial vehicles (UAVs) to collect information from distributed sensors is expected to be a promising solution in Internet of Things (IoT), especially for time-critical applications. How to maintain the information freshness is a challenging issue. In this paper, we investigate the fresh data collection problem in UAV-assisted IoT networks. Particularly, the UAV flies towards the sensors to collect status update packets within a given duration while maintaining a non-negative residual energy. We formulate a Markov Decision Process (MDP) to find the optimal flight trajectory of the UAV and transmission scheduling of the sensors that minimizes the weighted sum of the age of information (AoI). A UAV-assisted data collection algorithm based on deep reinforcement learning (DRL) is further proposed to overcome the curse of dimensionality. Extensive simulation results demonstrate that the proposed DRL-based algorithm can significantly reduce the weighted sum of the AoI compared to other baseline algorithms.

关键词： sensors Trajectory Data collection Unmanned aerial vehicles Internet of Things wireless sensor networks Energy consumption

PHY Security Enhancement Exploiting STAR-RIS for Dual-Functional Radar-communication

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PHY Security Enhancement Exploiting STAR-RIS for Dual-Functi...

IEEE International Conference on communications Workshops, ICC

作者： Chao Wang Cheng-Cai Wang Zan Li Derrick Wing Kwan Ng Kai-Kit Wong State Key Laboratory of Integrated Service Network Xidian University Xi'an China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology NJUPT Nanjing China School of Automation Science and Electrical Engineering Beihang University Beijing China School of Electrical Engineering and Telecommunications University of New South Wales Sydney Australia Department of Electronic and Electrical Engineering University College London London UK

Considering a simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RIS)-aided dual-functional radar-communications (DFRC) system, this paper proposes a symbol-level precoding-based scheme for enhancing the physical layer (PHY) security of the confidential information transmission and performing target sensing simultaneously. Specifically, the STAR-RIS-aided DFRC system design objective is to maximize the average received radar sensing power subject to the quality-of-service constraints for multiple communication users, the security constraint for multiple potential eavesdroppers, as well as various practical waveform design restrictions. However, the formulated problem is challenging to handle due to its nonconvexity. To address these issues, we propose a distance-majorization induced low-complexity algorithm to obtain an efficient solution. Simulation results confirm the effectiveness of the STAR-RIS in improving the DFRC performance.

关键词：

Traffic Matrix Prediction in SDN based on Spatial-Temporal Residual Graph Convolutional network

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Traffic Matrix Prediction in SDN based on Spatial-Temporal R...

第35届中国控制与决策会议

作者： Xintong Wang Yibo Sun Xuan Wang Enliang Wang Zhixin Sun Post Big Data Technology and Application Engineering Research Center of Jiangsu Province Nanjing University of Posts and Telecommunications Post Industry Technology Research and Development Center of the State Posts Bureau (Internet of Things Technology) Nanjing Universiry of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and Telecommunications School of Information Technology and Electrical Engineering The University of Queensland Brisbane

Traffic prediction is the basis for dynamic network services and resource *** Defined networking(SDN) provides a global view for network measurement and management,and a reliable way for network information collection and network traffic ***,SDN traffic prediction model enabled by deep learning mainly focuses on mining the temporal correlation of traffic data,while the modeling of its spatial correlation remains to be *** the perspective of the problem,a novel Spatial-Temporal Residual Graph Convolutional network(STRGCN) model for SDN Traffic Matrix(TM) prediction is *** with SDN network topology,TM prediction is defined as time series data prediction in non-Euclidean *** GatedConv Blocks are based on Gated Convolutional Layer,and Spatial Graph-Conv Blocks are based on Graph Convolutional network(GCN).Through identity mapping between SpatialTemporal Conv Blocks,the deep spatial and temporal features extraction is *** by TM data from CERNET and GEANT datasets,the accuracy and the timely performance of our model are *** results suggest that the general performance of STRGCN for TM prediction in SDN is superior to the current deep learning models.

关键词： software defined networking traffic prediction traffic matrix graph convolutional neural network spatialtemporal residual graph network

Logic W-state concentration with parity check

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Quantum Engineering

Quantum Engineering 2021年第2期3卷

作者： Zhou, Lan Liu, Jiu Liu, Ze-Kai Zhong, Wei Sheng, Yu-Bo School of Science Nanjing University of Posts and Telecommunications Nanjing China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing China College of Telecommunications & Information Engineering Nanjing University of Posts and Telecommunications Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China

Logic W state, which replaces each physical qubit in a W state with a Greenberger–Horne–Zeilinger state is robust against photon transmission loss in long-distance quantum communication. In practical application, the environmental noise may make maximally entangled logic W state degrade to less entangled state, which largely limits its application. In this article, we propose an efficient entanglement concentration protocol (ECP) for logic W state, which can recover the less entangled logic W state into the maximally entangled logic W state. Our ECP relies on the nondemolition polarization parity check (PPC) gate constructed with cross-Kerr nonlinearity. The distilled maximally entangled logic W state can be preserved for other application. Moreover, when the ECP fails, we can repeat the ECP to further concentrate the distilled less entangled logic W state. By repeating the ECP, the total success probability can be effectively increased. Based on above features, this ECP may be useful in quantum communication field. © 2021 John Wiley & Sons, Ltd.

关键词： Polarization