[en] A scheme for probabilistic teleportation of an unknown three-atom entangled state via a five-atom non-maximally entangled cluster state as quantum channel is proposed. In this scheme, the sender performs two Bell state and a single-atom measurements on the atoms, the receiver can reconstruct the original state with a certain probability by introducing an auxiliary atom and operating appropriate unitary transformations and controlled-not (C-not) operations according to the sender Alice's measurement results. As a result, the probability of successful teleportation is determined by the smallest two of the coefficients' absolute values of the cluster state. The considerable advantage of our scheme is that we employ a non-maximally entangled cluster state as quantum channel in the scheme, which can greatly reduce the amount of entanglement resources and need less classical bits. If we employ a maximally entangled cluster state as quantum channel, the probabilistic teleportation scheme becomes usual teleportation, the successful probability being 100%. (general)

[en] Quantum correlation is the workhorse of quantum information processing tasks. It is well known that the correlation in open system is unavoidably decayed. Here, we investigate the dynamics of Bell correlation when a bipartite state interacts with a relativistic frame and noisy environment. Based on quantum partially collapsing measurement, we then propose two feasible schemes to protect the degraded Bell correlation and demonstrate that our schemes are valid. At last, we explore the trade-off relation between success probability and measurement strength. The larger the measurement strength, the less probability of success. (paper: quantum statistical physics, condensed matter, integrable systems)

[en] We present a controllable scheme for transferring quantum state by means of an XY-type exchange interaction of flux qubits. In our scheme, the qubit encoding the state and the two neighboring qubits of channel is evolved under controllable Hamiltonian, and lastly, the single-qubit Pauli rotation operation is executed in the output qubit. Then, an arbitrary single-qubit state can be successfully transferred with high fidelity. At the same time, we compare the required total time for performing all transfer steps with systematical decoherent time and declare that our scheme is valid within current quantum experimental technology. (letter)

[en] We propose a nanostructure composed of a thick metallic rod with a cavity, in which multiple out-of-plane plasmonic resonances can be excited. When the cavity is laterally shifted to form an asymmetric nanostructure, the coupling between the plasmonic resonances excited in an individual element of the rod produces high-order hybridized out-of-plane modes with narrow linewidth. A further analysis reveals that the hybridized modes have Fano-like spectral line-shapes, which can be accurately described by a coupled oscillator model. (letter)

[en] By virtue of the quantum-memory-assisted entropic uncertainty relation (EUR), we analyze entanglement witness via the efficiencies of the estimates proposed by Berta (2010 Nat. Phys. 6 659) and Pati (2012 Phys. Rev. A 86 042105). The results show that, without a structured reservoir, the entanglement regions witnessed by these EUR estimates are only determined by the chosen estimated setup, and have no correlation with the explicit form of the initial state. On the other hand, with the structured reservoirs, the time regions during which the entanglement can be witnessed, and the corresponding entanglement regions closely depend on the choice of the estimated setup, the initial state and the state purity $p$. Concretely, for a pure state with $p=1$, the entanglement can be witnessed by both estimates, while for mixed states with $p=0.78$, it can only be witnessed using the Pati estimate. What is more, we find that the time regions incorporating the Pati estimate become discontinuous for the initial state with $|{\mathrm{\varphi <!--\; ??\; -->}}^{\mathrm{\prime <!--\; ???\; -->}}⟩=(|01⟩+|10⟩)/\sqrt{2}$, and the corresponding entanglement regions remain the same; however the entanglement can only be witnessed once by utilizing the Berta estimate. (letter)

[en] Quantum coherence (QC) as a crucial physical resource plays the vital role in recent researches of quantum information science, whereas the QC within an open system unavoidably deteriorates due to the system–environment interacting. In this paper, we analyze the dynamics of QC when the initial state is exposed to Markovian and non-Markovian reservoirs, respectively. We analytically derive the dynamical conditions under which the QC is frozen in the Markovian reservoir and explore the underlying physical mechanisms by investigating the trade-off relation between QC and mixedness of system. In the non-Markovian reservoir, we demonstrate the damped revivals of QC and show that these revivals can be effectively enhanced by increasing the memory degree of reservoir. These findings might provide an insightful physical interpretation for the dynamical phenomena of QC exhibiting in complex systems.