One-step implementation of multi-qubit conditional phase gating with nitrogen-vacancy centers coupled to a high-Q silica microsphere cavity

The diamond nitrogen-vacancy (NV) center is an excellent candidate for quantum information processing, whereas entangling separate NV centers is still of great experimental challenge. We propose an one-step conditional phase flip with three NV centers coupled to a whispering-gallery mode cavity by virtue of the Raman transition and smart qubit encoding. As decoherence is much suppressed, our scheme could work for more qubits. The experimental feasibility is justified.Comment: 3 pages, 2 figures, Accepted by Appl. Phys. Let

Nucleation in binary polymer blends: Effects of adding diblock copolymers

The effects of adding AB diblock copolymers to A/B binary blends on the structure and thermodynamics of critical nuclei are studied using the self-consistent field theory. At a fixed ratio of the amount of the two homopolymers, depending on the degree of polymerization and composition of the diblocks, their addition to the blends can either increase or decrease the nucleation free energy barrier relative to the pure A/B blends. The qualitative trend can be deduced from the shift in the coexistence boundary and the spinodal. The distribution of diblock copolymers in critical nuclei depends on the composition of the diblocks and the quench depth. Near the coexistence, symmetric diblocks exhibit surfactant behavior, being highly concentrated on the interface of the critical nuclei. Near the spinodal, they act more like co-solvent with a relatively uniform distribution

Effects of tidally enhanced stellar wind on the horizontal branch morphology of globular clusters

Metallicity is the first parameter to influence the horizontal branch (HB) morphology of globular clusters (GCs). It has been found, however, that some other parameters may also play an important role in affecting the morphology. While the nature of these important parameters remains unclear, they are believed to be likely correlated with wind mass-loss of red giants, since this mass loss determines their subsequent locations on the HB. Unfortunately, the mass loss during the red giant stages of the stellar evolution is poorly understood at present. The stellar winds of red giants may be tidally enhanced by companion stars if they are in binary systems. We investigate evolutionary consequences of red giants in binaries by including tidally enhanced stellar winds, and examine the effects on the HB morphology of GCs. We find that red, blue, and extreme horizontal branch stars are all produced under the effects of tidally enhanced stellar wind without any additional assumptions on the mass-loss dispersion. Furthermore, the horizontal branch morphology is found to be insensitive to the tidal enhancement parameter, Bw. We compare our theoretical results with the observed horizontal branch morphology of globular cluster NGC 2808, and find that the basic morphology of the horizontal branch can be well reproduced. The number of blue horizontal branch stars in our calculations, however, is lower than that of NGC 2808.Comment: 7 pages, 4 figures, 2 tables, accepted for publication in Astronomy & Astrophysic

Examining Individuals’ Utilization of SPOC: Extending the Task-Technology Fit Model with Online and Offline Perspective

Small Private Online Course (SPOC) platform enables individuals to carry out their learning tasks both online and offline. In order to understand individuals’ utilization of SPOC, this study develops a research model to examine the joint influences of three types of perceived fit manifested in perceived technology-task fit (TTF), perceived individual-technology fit (ITF) and perceived online-offline fit (OOF). A survey was conducted in a famous university of China and 371 data were collected from students who selected courses on the SPOC platform. Structural equation modelling method was used to examine the research model. The empirical results suggest that ITF is the most significant antecedent of individual performance expectancy, followed by OOF and TTF. Moreover, individual performance expectancy has a positive influence on user satisfaction and individuals’ continuance intention in the SPOC platform. A post-hoc analysis further indicates that student’s GPA positively moderates the relationship between online participation behavior and course performance. This study extends the traditional perceived fit framework by introducing perceived online-offline fit, and uncovers the antecedents and outcomes of individuals’ utilization in the emerging research context of SPOC