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We present a practical and general scheme of remote state preparation in the presence of the classical non-Markovian noises, where one of the quantum channels becomes a mixed state. The noises can be modelled as the so-called Ornstein-Uhlenbeck processes. This remote state preparation scheme is more practical than the pure state case in quantum information processing. The fidelity of the remote state preparation is (1 + e −4f(t))/2 and the success probability is 1/2.

We study the dynamics of geometric measure of quantum discord (GMQD) under the influences of two local phase damping noises. Consider the two qubits initially in arbitrary X-states, we find the necessary and sufficient conditions for which GMQD is unaffected for a finite period. It is further shown that such results also hold for the non-Markovian dephasing process., Comment: 4 pages, 2 figures

A general protocol for constructing a complete efficient encoding and decoding quantum circuit of the [[8,3,5]] stabilizer code is proposed. The [[8,3,5]] stabilizer code is an eight-qubit code that protects a three-qubit state with up to one error, which is very important for quantum information processing. Single-qubit operations, two-qubit controlled gates and Toffoli gates are required in the proposed circuit. The current protocol can be generalized to all quantum stabilizer codes satisfying quantum Hamming bound, and implemented in some quantum systems.

Currently, scalability and decoherence are still the two crucial problems for realizing large-scale quantum computation. To transfer information efficiently in the field of quantum computer and quantum communication, we must solve the two problems reasonably. Here, we propose an efficient scheme for the implementation of quantum states transfer in different couplings of superconducting devices, which are coupled weakly over a long distance. It is found that the isotropic Heisenberg coupling can offer the perfect operation for arbitrary states transfer with the shortest time. The scheme is feasible because the couplings have been demonstrated in actual experiments recently.

We propose an entanglement swapping scheme for mixed states in a classical non-Markovian noises, which is modelled as the so-called Ornstein-Uhlenbeck processes. The two mixed states before entanglement swapping are two X-type mixed states, which are caused by the environment-induced decoherence on the initially Bell states. This is more practical than the pure state case in quantum information processing. The fidelity and concurrence of the post-swapping states are discussed.

We evaluate the dynamics of two-qubit quantum discord(QD) under the classical phase noise. We compare the dynamics of QD with that of entanglement as measured with concurrence. The influence of mixture degree on the dynamics is also discussed. The results show that there is no simple relation between the quantum correlation and entanglement as seen that QD may be smaller or larger than entanglement, and QD is more robust than the entanglement.

Using the factorization Law for entanglement decay derived by Konrad, T., et al.: Nature Phys. 4, 99 (2008), we investigate the one-side and two-side local decoherence effect on the dynamics of the two-qubit entangled states. Under the depolarizing channel and GAD channel with the nonzero temperature, we have found that any two-qubit states will experience ESD. Furthermore, we also investigate the entanglement dynamics under the non-Markovian case.

We propose two schemes for entanglement generation and quantum state transfer via a double-quantum-dot system. Our schemes only need spin-parity measurements and single-qubit measurements combined with additional qubits. Discussions about the feasibility of the current scheme show that they would be realized within the current experimental technology.