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Three-Tangle for High-Rank Mixed States

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Communications in Theoretical Physics 2011年第2期55卷 251-256页

作者：何淑娟王晓红费少明孙洪祥温巧燕 State Key Laboratory of Networking and Switching Technology Beijing University of Post and Telecommunication department of Mathematics Capital Normal University School of Science Beijing University of Post and Telecommunication

A family of rank-n （n = 5, 6, 7, 8） three-qubit mixed states are constructed. The explicit expressions for the three-tangle and optimal decompositions for all these states are given. The CKW relations for these stat... 详细信息

关键词： three-tangle optimal decomposition

Scheme for Implementing Controlled Dense Coding with Six-Atom Cluster State in Cavity QED

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Communications in Theoretical Physics 2013年第5期59卷 559-562页

作者：李渊华李翠翠王贤平桑明煌聂义友 department of Physics Jiangxi Normal University Key Laboratory of Optoelectronic & telecommunication of Jiangxi Province State Key Laboratory of Advanced Optical Communication systems and Networks Shanghai Jiao Tong University

We propose an experimentally feasible protocol for implementing controlled dense coding with a six-atom duster state in cavity QED. In the scheme, we investigate that the atoms interact simultaneously with the highly detuned single-mode cavity and the strong classical driving field, and thus our scheme is not sensitive to both the cavity decay and the thermal field, in addition, the four-atom entangled states can be exactly distinguished by performing the single-atom measurements in cavity QED, therefore our scheme might be implemented in a simple way.

关键词： quantum information controlled dense coding six-atom cluster state cavity QED

A trust framework based smart aggregation for machine type communication

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Science China(Information Sciences) 2017年第10期60卷 78-92页

作者： Tabinda SALAM Waheed ur REHMAN Xiaofeng TAO Yu CHEN Ping ZHANG National Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and Telecommunication department of Computer Science University of Peshawar

Machine type communication(MTC) is one of the significant communication paradigms in the fifth generation networks. The existing cellular networks are not designed for massive access of the MTC ***, data aggregation and relaying are advocated to reduce the massive MTC access besides other physical layer solutions. In this paper, we propose a secured multiple mobile relay selection algorithm that smartly aggregates data from adjacent MTC devices through multiple user equipments and transmits it to the base station(BS). The paper also presents a framework for the selection of trusted relays to cooperatively aggregate MTC data and render two-hop connectivity to the BS. Our proposed algorithm is compared with existing algorithms on the basis of energy efficiency, system capacity, communication delay and outage probability. Our proposed algorithm outperforms the other schemes by improving outage probability and communication delay by 33% and 25%, respectively.

关键词： D2D communication data aggregation machine type communication(MTC) mobile relay MTC offloading

Influence of Composite Effect from Quantum Channels on Entanglement

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Communications in Theoretical Physics 2014年第8期61卷 183-188页

作者：胡菊菊李帅 department of Physics Jiangxi Normal University Key Laboratory of Photoelectronics and telecommunication of Jiangxi Province

The dynamics of entanglement between two qubits in the local damping two-sided channel and singlesided channel are compared through non-Markovian process and Markovian process. The entanglement between two qubits is found to be longer in the single-sided channel case due to the weakening of the dissipative effects. In the two-sided channel, influenced by the entanglement between qubits, the previous independent dissipative channels incline to the composite effect of the Markovian process. This composite effect results in the dissipative effect of one channel affecting the qubits in the other channel, especially inhibiting the backflow effect in the non-Markovian channel, which is disadvantageous to the entanglement maintenance between qubits. In the Markovian channel, the composite effect of the damping two-sided channels is more obvious since there is no backflow effect, thus more disadvantageous to the entanglement maintenance.

关键词： entanglement non-Markovian process quantum channel composite effect

Study on Intermittent Multiqueue Network Conservation Law

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Chinese Science Bulletin 1993年第8期38卷 688-693页

作者：逯昭义王思明 department of Electronics Lanzhou University department of telecommunication Lanzhou Railway Institute

Study on optical gain of one-dimensional photonic crystals with active impurity

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Chinese Optics Letters 2007年第12期5卷 696-699页

作者：李正华沈廷根宋雪桦马俊峰盛勇王刚 telecommunication T&R Section Zhenjiang Watercraft CollegeZhenjiang 212003 Institute of Applied PhysicsJiangsu UniversityZhenjiang 212013 Department of Electronic EngineeringEast China Normal UniversityShanghai 200062 Institute of Applied Physics Jiangsu UniversityZhenjiang 212013 Department of Telecommunication EngineeringJiangsu UniversityZhenjiang 212013 department of telecommunication Engineering Jiangsu UniversityZhenjiang 212013

Localized fields in the defect mode of one-dimensional photonic crystals with active impurity are studied with the help of the theory of spontaneous emission from two-level atoms embedded in photonic crystals. Numerical simulations demonstrate that the enhancement of stimulated radiation, as well as the phenomena of transmissivity larger than unity and the abnormality of group velocity close to the edges of photonic band gap, are related to the negative imaginary part of the complex effective refractive index of doped layers. This means that the complex effective refractive index has a negative imaginary part, and that the impurity state with very high quality factor and great state density will occur in the photonic forbidden band if active impurity is introduced into the defect layer properly. Therefore, the spontaneous emission can be enhanced, the amplitude of stimulated emission will be very large and it occurs most probably close to the edges of photonic band gap with the fundamental reason, the group velocity close to the edges of band gap is verv small or abnormal.

关键词： Computer simulation One dimensional Optical gain Photonic band gap Refractive index Spontaneous emission Stimulated emission

Negative Lumped Element Matching Technique for Performance Enhancement of Ultra-Wideband LNA

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China Communications 2019年第3期16卷 143-153页

作者： Kishor G Sawarkar Kushal Tuckley Research Scholar at department of Electronics and telecommunication MCT's RGIT University of Mumbai IITB Mumbai

The paper aims at designing of two stage cascaded ultra-wideband(UWB) low noise amplifier(LNA) by using negative image amplifier technique. The objective of this article is to show the performance improvement using negative image amplifier technique and realization of negative valued lumped elements into microstrip line geometry. The innovative technique to realize the negative lumped elements are carried out by using Richard's Transformation and transmission line calculation. The AWR microwave office tool is used to obtain characteristics of UWB LNA design with hybrid microwave integrated circuit(HMIC) technology. The 2-stage cascaded LNA design using negative image amplifier technique achieves average gain of 23 dB gain and low noise Figure of less than 2 dB with return loss less than-8 dB for UWB 3-10 GHz. The Proper bias circuit is extracted using DC characteristics of transistor at biasing point 2 V, 20 mA and discussed in detail with LNA layout. The negative image matching technique is applied for both input and output matching network. This work will be useful for all low power UWB wireless receiver applications.

关键词： LNA ultrawide band pHEMT matching network HMIC

Algebraic constructions of asymptotically optimal two-dimensional optical orthogonal codes

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Chinese Science Bulletin 1997年第19期42卷 1659-1662页

作者： Xu, CQ Yang, YX department of Information Engineering Beijing University of Post and Telecommunication Beijing China

1 Preliminaries The mathematical definition of the two-dimensional optical orthogonal code(2-D OOC)is as follows: Definition 1. A(mn, ω,λ_a,λ_c) 2-DOOC consists of a set of(O, 1) m×n matri-

关键词： optical orthogonal codes CDMA optical communications coding.

Enhancement effect of asymmetry on the thermal conductivity of double-stranded chain systems

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Chinese Physics B 2011年第10期20卷 171-176页

作者：张茂平钟伟荣艾保全 department of Physics College of Science and Engineering Jinan University School of Physics and telecommunication Engineering South China Normal University

Using nonequilibrium molecular dynamics simulations, we study the thermal conductivity of asymmetric double chains. We couple two different single chains through interchain coupling to build three kinds of asymmetric double- stranded chain system： intrachain interaction, external potential, and mass asymmetric double chains. It is reported that asymmetry is helpful in improving the thermal conductivity of the system. We first propose double-heat flux channels to explain the influence of asymmetric structures on the thermal conductivity. The phonon spectral behaviour and finite size effect are also included.

关键词： thermal conductivity double-stranded chain asymmetric structures inter-chain flux