基于k-体分划的D-concurrence多体纠缠测度

对于有限维多体量子系统中的态,D-concurrence是一个重要的纠缠测度,在过去的十年中被深入探索。将D-concurrence的概念推广到k-体分划的多体量子系统,它可以度量多体量子态在k-体分划下的非经典纠缠性,并证明了纠缠测度的一些必要性质,包括在k-可分态下纠缠测度为0,在局部酉操作下不变,在局部操作和经典通信(LOCC)下不增。

Stage IV malignant transformation of mature cystic teratoma palliatively treated with concurrent chemoradiotherapy:A case report

BACKGROUND Malignant transformation(MT)of mature cystic teratoma(MCT)has a poor prognosis,especially in advanced cases.Concurrent chemoradiotherapy(CCRT)has an inhibitory effect on MT.CASE SUMMARY Herein,we present a case in which CCRT had a reduction effect preoperatively.A 73-year-old woman with pyelonephritis was referred to our hospital.Computed tomography revealed right hydronephrosis and a 6-cm pelvic mass.Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)revealed squamous cell carci-noma.The patient was diagnosed with MT of MCT.Due to her poor general con-dition and renal malfunction,we selected CCRT,expecting fewer adverse effects.After CCRT,her performance status improved,and the tumor size was reduced;surgery was performed.Five months postoperatively,the patient developed dis-semination and lymph node metastases.Palliative chemotherapy was ineffective.She died 18 months after treatment initiation.CONCLUSION EUS-FNB was useful in the diagnosis of MT of MCT;CCRT suppressed the disea-se and improved quality of life.

二体四维量子系统的广义concurrence

将Wootters的concurrence推广到了二体四维情形.作为一个解析的实例,计算了一类二体四维对称态的广义concurrence.

多值交互时序逻辑的模型检验研究

为了对包含多值信息的开放系统进行形式化验证,在多值逻辑的基础上提出了多值交互时序逻辑并研究了该逻辑的模型检验问题。首先,引入多值并发博弈结构作为此类开放系统的模型,该模型的最大特点是可以建模带有多值信息的开放系统。其次,给出基于此模型的多值交互时序逻辑的语法和语义,该逻辑可以描述带有多值信息的待验证属性。最后,基于不动点理论给出多值交互时序逻辑的模型检验算法,并对算法的时间复杂度进行了分析,结果表明,可以在多项式时间内完成对多值交互时序逻辑的模型检验。

Mathematica在计算concurrence中的应用

利用Mathematica计算量子信息领域中的concurrence的一个程序，可以大大减少计算工作量。

文学广告的场域竞合与再造——基于我国现当代文学广告演变的思考

文学广告是文学作品推广与接受的重要手段之一,文学广告的运行机制是通过文学广告场域中“他律极”与“自主极”之间的竞合与再造完成的。研究对现当代文学广告场域的机制与作用进行了考察,在总结历史经验、观察现实媒介运行的基础上提出文学广告的传播新思路:借助媒介技术的创新再造文学广告场域———需要以整合传播的视角看待文学广告,以开放包容的心态去接纳电影、文学奖项、新书发售会、直播等新的传播中介,需要推动文学广告传播的定制化、差异化和分众化变革,需要实现文学创造力与市场化的平衡,以此激发广大读者阅读文学作品的热情。

Channel＇s Concurrence and Quantum Teleportation

Concurrence can measure the entanglement property of a system. If the channel is a pure state, positive concurrence state can afford the good performance in the teleportation process. If the channel ia a mixed state, positive concurrence state cannot assure the good performance in the teleportation. The conditions of the positive concurrence and the quantum teleportation in the Heisenberg spin ring is derived.

Concurrence of Quantum States: Algebraic Dynamical Method Study XXX Models in a Time-Depending Random External Field

Based on algebraic dynamics and the concept of the concurrence of the entanglement, we investigate the evolutive properties of the two-qubit entanglement that formed by Heisenberg XXX models under a time-depending external field. For this system, the property of the concurrence that is only dependent on the coupling constant J and total values of the external field is proved. Furthermore, we found that the thermal concurrence of the system under a static random external field is a function of the coupling constant J, temperature T, and the magnitude of external field.

Simple Scheme for Directly Measuring Concurrence of Two-Qubit Pure States in One Step

In the present work, a simple scheme for the direct measurement of the concurrence of two-qubit pure states is proposed. The scheme is based on trapped ions and only needs one step when the two identical pure states are given. The vibrational mode in our proposal is only virtually excited, which is important in view of decoherence.Furthermore, the scheme is feasible based on current technologies.

Direct measurement of the concurrence of hybrid entangled state based on parity check measurements

The hybrid entangled state is widely discussed in quantum information processing. In this paper, we propose the first protocol to directly measure the concurrence of the hybrid entangled state. To complete the measurement, we design parity check measurements(PCMs) for both the single polarization qubit and the coherent state. In this protocol, we perform three rounds of PCMs. The results show that we can convert the concurrence into the success probability of picking up the correct states from the initial entangled states. This protocol only uses polarization beam splitters, beam splitters, and weak cross-Kerr nonlinearities, which is feasible for future experiments. This protocol may be useful in future quantum information processing.

Eigenfunctions of Five-Qubit XX Chain and Ground State Concurrence

Use Jordan-Wigner transformation the eigenstates and eigenenergies of live qubits XX chain including external magnetic field are obtained. The concurrences Co,1 and Co,2 of ground state are obtained. For the ferromagnetic, when [（√5 - 1）/2]｜J｜ 〈 B ≤ ｜J｜, the values of C0,1 and C0,2 are the same. The C0,2 is easily broken by temperature.

Concurrence,tangle and fully entangled fraction

We show that although we cannot distil a singlet frora many pairs of bound entangled states, the concurrence and the tangle of two entangled quantum states are always strictly larger than those of one of them, even both entangled quantum states are bound entangled. We present a relation between the concurrence and the fidelity of optimal teleportation. We also give new upper and lower bounds for concurrence and tangle.

Application of quantum algorithms to direct measurement of concurrence of a two-qubit pure state

This paper proposes a method to measure directly the concurrence of an arbitrary two-qubit pure state based on a generalized Grover quantum iteration algorithm and a phase estimation algorithm. The concurrence can be calculated by applying quantum algorithms to two available copies of the bipartite system, and a final measurement on the auxiliary working qubits gives a better estimation of the concurrence. This method opens new prospects of entanglement measure by the application of quantum algorithms. The implementation of the protocol would be an important step toward quantum information processing and more complex entanglement measure of the finite-dimensional quantum system with an arbitrary number of qubits.

Study of Concurrence and D-Concurrence on Two-Qubits Resulted in Pair Coherent States in Language of SU(2) Coherent States

Pair coherent state, is a state of a two-mode radiation field that is known as a state with non-gaussian wave function. In this paper, study on the pair coherent state, we notice that with superposition of two first terms of this states, one two-qubits formed. Because of the importance of two-qubits in theory of quantum entanglement, with two different measures with the title of concurrence and D-concurrence, we have studied the amount of entanglement and discussed its details. At the end, we describe these measures for pair coherent states as a function of the amplitude of the SU（2） coherent states.

A Probability Measure for Entanglement of Pure Two-Qubit Systems and a Useful Interpretation for Concurrence

A new probability measure for the quantification of entanglement of pure states is introduced.Numerical computations indicate that the derived measure is equal to concurrence,up to the precision of the computer program used.Hence it also provides a physical interpretation for concurrence.

Randomly Generating Four Mixed Bell-Diagonal States with a Concurrences Sum to Unity

A two-qubit system in quantum information theory is the simplest bipartite quantum system and its concurrence for pure and mixed states is well known.As a subset of two-qubit systems,Bell-diagonal states can be depicted by a very simple geometrical representation of a tetrahedron with sides of length 2√2.Based on this geometric representation,we propose a simple approach to randomly generate four mixed Bell decomposable states in which the sum of their concurrence is equal to one.

Mutual Restriction between Concurrence and Intrinsic Concurrence for Arbitrary Two-Qubit States

Concurrence is viewed as the most commonly approach for quantifying entanglement of two-qubit states,while intrinsic concurrence contains concurrence of four pure states consisting of a special pure state ensemble concerning an arbitrary two-qubit state.Thus,a natural question arises:Whether there is a specified relation between them.We firstly examine the relation between concurrence and intrinsic concurrence for the maximally nonlocal mixed state under a special unitary operation,which is not yet rigorously proved.In order to obtain a general result,we investigate the relation between concurrence and intrinsic concurrence using randomly generated two-qubit states,and derive an inequality relation between them.Finally,we take into account the relation between concurrence and intrinsic concurrence in open systems,and reveal the ratio of the two quantum resources,which is only correlated with the experiencing channels.

A Surfing Concurrence Transaction Model for Key-Value NoSQL Databases

As more and more application systems related to big data were developed, NoSQL (Not Only SQL) database systems are becoming more and more popular. In order to add transaction features for some NoSQL database systems, many scholars have tried different techniques. Unfortunately, there is a lack of research on Redis’s transaction in the existing literatures. This paper proposes a transaction model for key-value NoSQL databases including Redis to make possible allowing users to access data in the ACID (Atomicity, Consistency, Isolation and Durability) way, and this model is vividly called the surfing concurrence transaction model. The architecture, important features and implementation principle are described in detail. The key algorithms also were given in the form of pseudo program code, and the performance also was evaluated. With the proposed model, the transactions of Key-Value NoSQL databases can be performed in a lock free and MVCC (Multi-Version Concurrency Control) free manner. This is the result of further research on the related topic, which fills the gap ignored by relevant scholars in this field to make a little contribution to the further development of NoSQL technology.

A Comparison of the Concurrence and the Quantum Discord in a Two-Qubit System

The quantum correlation dynamics in an anisotropic Heisenberg XY Z model under decoherence are investigated with the use of concurrence C and quantum discord （QD）. There is a remarkable difference between the time evolution behaviors of these two correlation measures： there is a entanglement-sudden-death phenomenon in the concurrence while there is none in QD, which is valid for all of the initial states of this system, and the interval time of the entanglement death is found to be strongly dependent on the initial states and the parameters B and △. With the long-time limit the steady entanglement （SC） and steady quantum discord （SO, D） can be obtained. The magnitudes of SC and SQD are closely related to the parameters B and △, while the strength of the Dzyaloshinskii-Moriya interaction, D, has no influence. In addition, the effects of the parameters B and △ on SC and SQD display such different and complicated features that one cannot obtain a uniform law about them, thus we give an analytical explanation of this phenomenon. Lastly, it can be noted that the value of SC is not always larger than SQD, which is strongly dependent on the parameters B and △.

Concurrence and Turnout Effect of Reforms on Electoral Processes in Mexico

Since the 1990s, the turnout in electoral processes has decreased, taking into account the Mexican context with its democratic transition, this decrease started after the 1994 federal election. The drop in turnout in federal elections had its lowest figure during the midterm elections of 2003, it picked up during the electoral process of 2009 and kept the same level of 2012. The change in the electoral turnout pattern for the federal elections in Mexico after 2009 can be explained as the combined effect of the electoral cycle and the concurrence between federal and local elections. Beginning from the hypothesis that there is a close link between institutions and contexts, the purpose of this study is to prove with the analysis of the electoral processes from 1997 to 2012, the effect of the electoral reforms--specifically the one in Article 116 of the Constitution in 2007-on turnout for federal elections of 2009 and 2012.