Non-Markovianity and coherence of a moving qubit inside a leaky cavity

Non-Markovian features of a system evolution, stemming from memory effects, may be utilized to transfer, storage, and revive basic quantum properties of the system states. It is well known that an atom qubit undergoes non-Markovian dynamics in high quality cavities. We here consider the qubit-cavity interaction in the case when the qubit is in motion inside a leaky cavity. We show that, owing to the inhibition of the decay rate, the coherence of the traveling qubit remains closer to its initial value as time goes by compared to that of a qubit at rest. We also demonstrate that quantum coherence is preserved more efficiently for larger qubit velocities. This is true independently of the evolution being Markovian or non-Markovian, albeit the latter condition is more effective at a given value of velocity. We however find that the degree of non-Markovianity is eventually weakened as the qubit velocity increases, despite a better coherence maintenance.Comment: 16 pages and 5 figures. Written for the upcoming special volume "40 years of the GKLS equation", to be published in the journal Open Systems and Information Dynamics. A co-author and some references adde

Polarity engineering in polycrystalline ZnO by inversion boundaries

Two distinctive polarity-engineered microstructures were obtained in polycrystalline ZnO ceramics by inducing two different types of inversion boundaries (IBs) inside individual grains to examine the effect of the different polarities on the varistor performances. The presence of head-to-head IBs induced by the addition of Sb and tail-to-tail IBs by doping Ti was directly confirmed by the characteristic geometry of the chemical etch pits. It was proposed that a consequent polarity on the grain boundary planes, which are affected by the presence of head-to-head IBs is crucial in exhibiting the superior performance of ZnO varistors.open2

Financial Stress in the Asian Christian Immigrant Community During COVID-19

The purpose of the current study was to examine how individual, economic, and psychological factors contributed to the financial concerns of Asian Christian immigrants in the U.S. during the COVID-19 pandemic (i.e., the impact of COVID-19 on employment status and income change, intolerance of uncertainty, hope, and personal meaning in life). The sample consisted of 103 immigrants from three East Asian countries affiliated with Christian churches. A hierarchical regression analysis was conducted to observe how the aforementioned variables predicted the participants’ financial worries. The results showed that intolerance of uncertainty accounted for a significant amount of variance in financial worries among the participants, but the impact of COVID-19, hope, and meaning in life did not predict significant variance. Implications for practice and future research were discussed

Vertical Dimensions of Mandible in Class II Subdivision Malocclusion with Skeletal Asymmetry

• Advancements in 3-dimensional imaging analysis, utilizing cone-beam computed tomography (CBCT), have allowed for further investigation of skeletal asymmetry. • While past 2-dimensional studies attributed dentoalveolar deviation to unilateral Class II malocclusion, recent 3D studies have found a primarily skeletal contribution.1 • There is much debate on the impact of condylar morphology on malocclusion in patients with Class II subdivision and significant skeletal asymmetry.2 • Some authors concluded that condylar characteristics are not correlated with skeletal asymmetry, while others reported a correlation between a greater condyle angulation and skeletal asymmetry.2-

Carbonation of surface protected concrete

Concrete structures are exposed to carbonation that may cause rapid decay, shortening their service life and raising maintenance and repair costs. Carbonation lowers the alkalinity of the concrete depassivating the steel reinforcement. Two limit states can be identified with regard to service life. The first limit state ends when the steel is depassivated. The second limit state is based on cracking of the concrete cover due to oxides generated during corrosion. The service life includes a certain propagation period of corrosion during which the cross-sectional area of steel is progressively decreased, the bond between steel and concrete is reduced and the effective cross-sectional area of concrete is diminished due to spalling of the cover. Surface treatment is commonly used to improve the resistance of concrete to carbonation. A barrier is formed retarding the carbonation reactions in the interior of the concrete. In this study surface protected concretes were compared with non-protected concretes. The used surface protected concretes presented generally lower carbonation diffusion coefficients than the non-protected concretes. The use of epoxy resin showed better protection than the use of acrylic and siloxane resins. The composition of the concretes is an important factor affecting the diffusion of carbonation. The influence of the water–cement ratio was very important. The carbonation diffusion coefficients increased with the water–cement ratio. The prescriptive methodology is not a guarantee to obtain the desired service lives of 50 or 100 years. The desired services lives were only obtained with the use of surface protection treatments