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71.
A quantum secret sharing (QSS) protocol between multiparty and multiparty is proposed, based on Greenberger-Horne- Zeilinger (GHZ) state. The protocol utilizes quantum Fourier transform and entanglement swapping to achieve a high intrinsic efficiency and source capacity. Then, the security of this protocol against some possible eavesdropping strategies has been analyzed. Furthermore, the presented protocol is generalized to the d-level case. 相似文献
72.
高斯型耦合Tavis-Cummings模型的纠缠特性 总被引:4,自引:1,他引:3
研究了高斯型耦合Tavis-Cummings模型的量子纠缠特性,利用量子约化熵研究了相干光场-双原子之间的纠缠,利用Negativity熵研究了两原子之间的纠缠,运用数值计算方法讨论了原子垂直于腔轴的运动速度和系统的初态对场-原子以及原子-原子纠缠的影响.结果表明,两种纠缠具有相似的时间演化规律,但对应于同一时刻,场-原子间的纠缠越强,两原子间的纠缠越弱.原子的运动速度对纠缠具有明显的调制作用;光场的初始光子数越大,熵的Rabi振荡频率越大,振幅越小;而改变原子的初态时,熵的时间演化规律是相似的. 相似文献
73.
磁场作用下XXZ模型的热力学纠缠 总被引:4,自引:3,他引:1
研究了一维带有外磁场的2量子比特XXZ模型的纠缠,得出它的纠缠度热力学解析表达式.通过计算表明,纠缠度在一定温度下随磁场各向异性参数的变化而展现的不同行为,发现系统纠缠对外磁场各项异性参数的变化非常敏感.当各向异性参数(△)固定时,纠缠关于磁场是对称分布;当各向异性参数(△)变大,纠缠很快地趋于零.此外,温度的变化对纠缠也有一定的影响.温度升高,系统纠缠的峰值不断减少,系统纠缠将完全消失. 相似文献
74.
75.
76.
Establishing entanglement is an essential task of quantum communication
technology. Beyond entanglement, quantum discord, as a measure of quantum
correlation, is a necessary prerequisite to the success of entanglement distribution. To
realize efficient quantum communication based on quantum discord, in this paper, we
consider the practical advantages of continuous variables and propose a feasible
continuous-variable quantum network coding scheme based on quantum discord. By
means of entanglement distribution by separable states, it can achieve quantum
entanglement distribution from sources to targets in a butterfly network. Compared with
the representative discrete-variable quantum network coding schemes, the proposed
continuous-variable quantum network coding scheme has a higher probability of
entanglement distribution and defends against eavesdropping and forgery attacks.
Particularly, the deduced relationship indicates that the increase in entanglement is less
than or equal to quantum discord. 相似文献
77.
Hossein Rangani Jahromi 《Journal of Modern Optics》2017,64(14):1377-1385
We address in detail the process of parameter estimation for an n-qubit system dissipating into a cavity in which the qubits are coupled to the single-mode cavity field via coupling constant g which should be estimated. In addition, the cavity field interacts with an external field considered as a set of continuum harmonic oscillators. We analyse the behaviour of the quantum Fisher information (QFI) for both weak and strong coupling regimes. In particular, we show that in strong coupling regime, the memory effects are dominant, leading to an oscillatory variation in the dynamics of the QFI and consequently information flowing from the environment to the quantum system. We show that when the number of the qubits or the coupling strength rises, the oscillations, signs of non-Markovian evolution of the QFI, increase. This indicates that in the strong-coupling regime, increasing the size of the system or the coupling strength remarkably enhances the reversed flow of information. Moreover, we find that it is possible to retard the QFI loss during the time evolution and therefore enhance the estimation of the parameter using a cavity with a larger decay rate factor. Furthermore, analysing the dynamics of the QFI and negativity of the probe state, we reveal a close relationship between the entanglement of probes and their capability for estimating the parameter. It is shown that in order to perform a better estimation of the parameter, we should avoid measuring when the entanglement between the probes is maximized. 相似文献
78.
超高分子量聚乙烯(UHMWPE)极高的分子量及线性分子链特性使其具备很多的优异性能,在军工、医药卫生等领域的应用越来越广泛的同时,对UHMWPE树脂的性能不断提出更高的要求。故利用高分辨扫描电镜(SEM)、高温凝胶色谱-红外联用(GPC-IR)、拉曼光谱(Raman)及差式扫描量热仪(DSC)对树脂初生态粒子的结晶结构、分子特性及热力学性能进行了研究,并通过控制模压过程中的冷却速率来研究UHMWPE样品的结晶行为,进而分析UHMWPE微观特性与宏观性能之间的关系。研究发现由次级颗粒和微纤组成的UHMWPE初生态粒子中具有大量的片晶和伸直链,分子链排列规整,结晶度高;但在熔融再结晶加工成制品的过程中,分子链的规整性遭到破坏,与初生态粒子相比,结晶度下降、缠结密度变大。另外,不同降温速率的样品中淬冷样品的分子链缠结密度最低,而低缠结、小的晶粒能够提升制品的耐冲击性能及断裂时的真应力。 相似文献
79.
基于量子纠缠交换理论,提出一种基于Bell态纠缠交换的量子盲签名方案。消息拥有者Alice将待签名消息发送给盲签名者Charlie,Charlie根据双方共享的量子密钥对消息进行盲化签名,加密后发送给消息验证者Bob。Bob收到盲化签名后,根据他与Charlie共享的量子密钥对签名进行验证。利用量子纠缠特性,实现了消息对签名者Charlie的盲化性。基于量子密钥分发和一次一密技术,保证了签名过程的绝对安全性。 相似文献
80.
In this paper, we present a novel deep generative facial parts swapping method: parts-swapping generative adversarial network (PSGAN). PSGAN independently handles facial parts, such as eyes (left eye and right eye), nose, mouth and jaw, which achieves facial parts swapping by replacing the target facial parts with source facial parts and reconstructing the entire face image with these parts. By separately modeling the facial parts in the form of region inpainting, the proposed method can successfully achieve highly photorealistic face swapping results, enabling users to freely manipulate facial parts. In addition, the proposed method is able to perform jaw editing based on sketch guidance information. Experimental results on the CelebA dataset suggest that our method achieves superior performance for facial parts swapping and provides higher user control flexibility. 相似文献