Unextendible Maximally Entangled Bases in Cpd⊗Cqd\mathbb{C}^{pd}\otimes \mathbb{C}^{qd}

The construction of unextendible maximally entangled bases is tightly related to quantum information processing like local state discrimination. We put forward two constructions of UMEBs in $\mathbb {C}^{pd}\otimes \mathbb {C}^{qd}$($p\leq q$) based on the constructions of UMEBs in $\mathbb {C}^{d}\otimes \mathbb {C}^{d}$ and in $\mathbb {C}^{p}\otimes \mathbb {C}^{q}$, which generalizes the results in [Phys. Rev. A. 94, 052302 (2016)] by two approaches. Two different 48-member UMEBs in $\mathbb {C}^{6}\otimes \mathbb {C}^{9}$ have been constructed in detail

Single-photon-triggered quantum chaos

We demonstrate how to manipulate quantum chaos with a single photon in a hybrid quantum device combining cavity QED and optomechanics. Specifically, we show that this system changes between integrable and chaotic relying on the photon-state of the injected field. This onset of chaos originates from the photon-dependent chaotic threshold of the qubit-field coupling induced by the optomechanical interaction. By deriving the Loschmidt Echo we observe clear differences in the sensitivity to perturbations in the regular versus chaotic regimes. We also present classical analog of this chaotic behavior, and find good correspondence between chaotic quantum dynamics and classical physics. Our work opens up a new route to achieve quantum manipulations, which are crucial elements in engineering new types of on-chip quantum devices and quantum information science.Comment: 11 pages, 4 figure

Human Disturbance Reduces Plant Species Diversity and Stability of Phyllostachys pubescens Forests

Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems. Human activity can completely alter plant species diversity and cause serious degradation of ecosystems but its impact on bamboo forest still lacks of systematic evaluation. In this study, we performed a field investigation to reveal the influences of human disturbances on the plant diversity and stability of Moso bamboo forests at Southern China. The selected bamboo fields contained different intensities of human activities that could be classified as slight, moderate and severe disturbance level. Species richness index S, Shannon-Wienner index H, Simpson index D, Pielou index Jsw, community similarity index IS and community stability index were employed to quantitatively evaluate the plant species diversity and stability. The survey revealed that there were 203 species belonging to 83 families and 108 genera in Moso bamboo forests. The number of plant species in the Moso bamboo forests decreased with the increasing of disturbance intensity. The species diversity indexes generally followed the order of slight > moderate > severe disturbance, as well as the richness index S, Shannon-Wienner index H and Pielou index Jsw. The similarity and species stability of the bamboo forest communities also decreased with the increase of the disturbance intensity. Under the severe disturbance, plant species replacement occurred strongly. The obtained results provide some a guideline for the sustainable management of bamboo forest