0.94(Na0.5Bi0.5+x)TiO3–0.06BaTiO3 (x = −0.04, 0, 0.02; named NB0.46T‐6BT, NB0.50T‐6BT, NB0.52T‐6BT, respectively) lead‐free piezoelectric ceramics were prepared via the solid‐state reaction method. Effects of Bi3+ nonstoichiometry on microstructure, dielectric, ferroelectric, and piezoelectric properties were studied. All ceramics show typical X‐ray diffraction peaks of ABO3 perovskite structure. The lattice parameters increase with the increase in the Bi3+ content. The electron probe microanalysis demonstrates that the excess Bi2O3 in the starting composition can compensate the Bi2O3 loss induced during sample processing. The size and shape of grains are closely related to the Bi3+ content. For the unpoled NB0.50T‐6BT and NB0.52T‐6BT, there are two dielectric anomalies in the dielectric constant–temperature curves. The unpoled NB0.46T‐6BT shows one dielectric anomaly accompanied by high dielectric constant and dielectric loss at low frequencies. After poling, a new dielectric anomaly appears around depolarization temperature (Td) for all ceramics and the Td values increase with the Bi3+ amount decreasing from excess to deficiency. The diffuse phase transition character was studied via the Curie–Weiss law and modified Curie–Weiss law. The activation energy values obtained via the impedance analysis are 0.69, 1.05, and 1.16 eV for NB0.46T‐6BT, NB0.50T‐6BT and NB0.52T‐6BT, respectively, implying the change in oxygen vacancy concentration in the ceramics. The piezoelectric constant, polarization, and coercive field of the ceramics change with the variation in the Bi3+ content. The Rayleigh analysis suggests that the change in electrical properties of the ceramics with the variation in the Bi3+ amount is related to the effect of oxygen vacancies.

Abstract. By analytically solving the master equation, we investigate quantum state transfer, creation and distribution of entanglement in the model of Milburn's intrinsic decoherence. Our results reveal that the ideal spin channels will be destroyed by the intrinsic decoherence environment, and the detrimental effects become severe as the decoherence rate γ and the spin chain length N increase. For infinite evolution time, both the state transfer fidelity and the concurrence of the created and distributed entanglement approach steady state values, which are independent of the decoherence rate γ and decrease as the spin chain length N increases. Finally, we present two modified spin chains which may serve as near perfect spin channels for long distance state transfer even in the presence of intrinsic decoherence environments F[ρ(t)].

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The reservoir memory effects can lead to information backflow and recurrence of the previously lost quantum correlations. We establish connections between the direction of information flow and variation of the geometric quantum discords (GQDs) measured respectively by the trace distance, the Hellinger distance, and the Bures distance for two qubits subjecting to the bosonic structured reservoirs, and unveil their dependence on a factor whose derivative signifies the (non-)Markovianity of the dynamics. By considering the reservoirs with Lorentzian and Ohmic-like spectra, we further demonstrated that the non-Markovianity induced by the backflow of information from the reservoirs to the system enhances the GQDs in most of the parameter regions. This highlights the potential of non-Markovianity as a resource for protecting the GQDs.

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