Assisted optimal state discrimination without entanglement

A fundamental problem in quantum information is to explore the roles of different quantum correlations in a quantum information procedure. Recent work [Phys. Rev. Lett., 107 (2011) 080401] shows that the protocol for assisted optimal state discrimination (AOSD) may be implemented successfully without entanglement, but with another correlation, quantum dissonance. However, both the original work and the extension to discrimination of $d$ states [Phys. Rev. A, 85 (2012) 022328] have only proved that entanglement can be absent in the case with equal a \emph{priori} probabilities. By improving the protocol in [Sci. Rep., 3 (2013) 2134], we investigate this topic in a simple case to discriminate three nonorthogonal states of a qutrit, with positive real overlaps. In our procedure, the entanglement between the qutrit and an auxiliary qubit is found to be completely unnecessary. This result shows that the quantum dissonance may play as a key role in optimal state discrimination assisted by a qubit for more general cases.Comment: 6 pages, 3 figures. Accepted by EPL. We extended the protocol for assisted optimal state discrimination to the case with positive real overlaps, and presented a proof for the absence of entanglemen

A basic helix-loop-helix transcription factor, PhFBH4, regulates flower senescence by modulating ethylene biosynthesis pathway in petunia.

The basic helix-loop-helix (bHLH) transcription factors (TFs) play important roles in regulating multiple biological processes in plants. However, there are few reports about the function of bHLHs in flower senescence. In this study, a bHLH TF, PhFBH4, was found to be dramatically upregulated during flower senescence. Transcription of PhFBH4 is induced by plant hormones and abiotic stress treatments. Silencing of PhFBH4 using virus-induced gene silencing or an antisense approach extended flower longevity, while transgenic petunia flowers with an overexpression construct showed a reduction in flower lifespan. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was significantly changed in petunia PhFBH4 transgenic flowers. Furthermore, silencing or overexpression of PhFBH4 reduced or increased, respectively, transcript abundances of important ethylene biosynthesis-related genes, ACS1 and ACO1, thereby influencing ethylene production. An electrophoretic mobility shift assay showed that the PhFBH4 protein physically interacted with the G-box cis-element in the promoter of ACS1, suggesting that ACS1 was a direct target of the PhFBH4 protein. In addition, ectopic expression of this gene altered plant development including plant height, internode length, and size of leaves and flowers, accompanied by alteration of transcript abundance of the gibberellin biosynthesis-related gene GA2OX3. Our results indicate that PhFBH4 plays an important role in regulating plant growth and development through modulating the ethylene biosynthesis pathway

Most robust and fragile two-qubit entangled states under depolarizing channels

For a two-qubit system under local depolarizing channels, the most robust and most fragile states are derived for a given concurrence or negativity. For the one-sided channel, the pure states are proved to be the most robust ones, with the aid of the evolution equation for entanglement given by Konrad et al. [Nat. Phys. 4, 99 (2008)]. Based on a generalization of the evolution equation for entanglement, we classify the ansatz states in our investigation by the amount of robustness, and consequently derive the most fragile states. For the two-sided channel, the pure states are the most robust for a fixed concurrence. Under the uniform channel, the most fragile states have the minimal negativity when the concurrence is given in the region [1/2,1]. For a given negativity, the most robust states are the ones with the maximal concurrence, and the most fragile ones are the pure states with minimum of concurrence. When the entanglement approaches zero, the most fragile states under general nonuniform channels tend to the ones in the uniform channel. Influences on robustness by entanglement, degree of mixture, and asymmetry between the two qubits are discussed through numerical calculations. It turns out that the concurrence and negativity are major factors for the robustness. When they are fixed, the impact of the mixedness becomes obvious. In the nonuniform channels, the most fragile states are closely correlated with the asymmetry, while the most robust ones with the degree of mixture.Comment: 10 pages, 9 figs. to appear in Quantum Information & Computation (QIC

Spatial Heterogeneity in Light Supply Affects Intraspecific Competition of a Stoloniferous Clonal Plant

Spatial heterogeneity in light supply is common in nature. Many studies have examined the effects of heterogeneous light supply on growth, morphology, physiology and biomass allocation of clonal plants, but few have tested those effects on intraspecific competition. In a greenhouse experiment, we grew one (no competition) or nine ramets (with intraspecific competition) of a stoloniferous clonal plant, Duchesnea indica, in three homogeneous light conditions (high, medium and low light intensity) and two heterogeneous ones differing in patch size (large and small patch treatments). The total light in the two heterogeneous treatments was the same as that in the homogeneous medium light treatment. Both decreasing light intensity and intraspecific competition significantly decreased the growth (biomass, number of ramets and total stolon length) of D. indica. As compared with the homogeneous medium light treatment, the large patch treatment significantly increased the growth of D. indica without intraspecific competition. However, the growth of D. indica with competition did not differ among the homogeneous medium light, the large and the small patch treatments. Consequently, light heterogeneity significantly increased intraspecific competition intensity, as measured by the decreased log response ratio. These results suggest that spatial heterogeneity in light supply can alter intraspecific interactions of clonal plants

OpenPARF: An Open-Source Placement and Routing Framework for Large-Scale Heterogeneous FPGAs with Deep Learning Toolkit

This paper proposes OpenPARF, an open-source placement and routing framework for large-scale FPGA designs. OpenPARF is implemented with the deep learning toolkit PyTorch and supports massive parallelization on GPU. The framework proposes a novel asymmetric multi-electrostatic field system to solve FPGA placement. It considers fine-grained routing resources inside configurable logic blocks (CLBs) for FPGA routing and supports large-scale irregular routing resource graphs. Experimental results on ISPD 2016 and ISPD 2017 FPGA contest benchmarks and industrial benchmarks demonstrate that OpenPARF can achieve 0.4-12.7% improvement in routed wirelength and more than $2\times$ speedup in placement. We believe that OpenPARF can pave the road for developing FPGA physical design engines and stimulate further research on related topics

A two-dimensional hybrid with molybdenum disulfide nanocrystals strongly coupled on nitrogen-enriched graphene via mild temperature pyrolysis for high performance lithium storage

A novel 2D hybrid with MoS₂ nanocrystals strongly coupled on nitrogen-enriched graphene (MoS₂/NGg-C₃N₄) is realized by mild temperature pyrolysis (550 °C) of a self-assembled precursor (MoS₃/g-C₃N₄–H⁺/GO). With rich active sites, the boosted electronic conductivity and the coupled structure, MoS₂/NGg₋C₃N₄ achieves superior lithium storage performance