Fidelity susceptibility and long-range correlation in the Kitaev honeycomb model

We study exactly both the ground-state fidelity susceptibility and bond-bond correlation function in the Kitaev honeycomb model. Our results show that the fidelity susceptibility can be used to identify the topological phase transition from a gapped A phase with Abelian anyon excitations to a gapless B phase with non-Abelian anyon excitations. We also find that the bond-bond correlation function decays exponentially in the gapped phase, but algebraically in the gapless phase. For the former case, the correlation length is found to be $1/\xi=2\sinh^{-1}[\sqrt{2J_z -1}/(1-J_z)]$, which diverges around the critical point $J_z=(1/2)^+$.Comment: 7 pages, 6 figure

Magnetic Topological Transistor Exploiting Layer-Selective Transport

We propose a magnetic topological transistor based on MnBi$_{2}$Te$_{4}$, in which the "on" state (quantized conductance) and the "off" state (zero conductance) can be easily switched by changing the relative direction of two adjacent electric fields (parallel vs. antiparallel) applied within a two-terminal junction. We explain that the proposed magnetic topological transistor relies on a novel mechanism due to the interplay of topology, magnetism, and layer degrees of freedom in MnBi$_{2}$Te$_{4}$. Its performance depends substantially on film thickness and type of magnetic order. We show that "on" and "off" states of the transistor are robust against disorder due to the topological nature of the surface states. Our work opens an avenue for applications of layer-selective transport based on the topological van der Waals antiferromagnet MnBi$_{2}$Te$_{4}$

The visualization of the space probability distribution for a particle moving in a double ring-shaped Coulomb potential

The analytical solutions to a double ring-shaped Coulomb potential (RSCP) are presented. The visualizations of the space probability distribution (SPD) are illustrated for the two-(contour) and three-dimensional (isosurface) cases. The quantum numbers (n, l, m) are mainly relevant for those quasi quantum numbers (n' ,l' ,m' ) via the double RSCP parameter c. The SPDs are of circular ring shape in spherical coordinates. The properties for the relative probability values (RPVs) P are also discussed. For example, when we consider the special case (n, l, m)=(6, 5, 0), the SPD moves towards two poles of axis z when the P increases. Finally, we discuss the different cases for the potential parameter b which is taken as negative and positive values for c>0 . Compared with the particular case b=0 , the SPDs are shrunk for b=-0.5 while spread out for b=0.5.Comment: 26 pages, 5 tables and 3 figures, Advances in High Energy Physics, in pres

The visualization of the space probability distribution for a moving particle I: in a single ring-shaped Coulomb potential

We first present the exact solutions of the single ring-shaped Coulomb potential and then realize the visualizations of the space probability distribution for a moving particle within the framework of this potential. We illustrate the two-(contour) and three-dimensional (isosurface) visualizations for those specifically given quantum numbers (n, l, m) essentially related to those so-called quasi quantum numbers (n',l',m') through changing the single ring-shaped Coulomb potential parameter b. We find that the space probability distributions (isosurface) of a moving particle for the special case and the usual case are spherical and circular ring-shaped, respectively by considering all variables in spherical coordinates. We also study the features of the relative probability values P of the space probability distributions. As an illustration, by studying the special case of the quantum numbers (n, l, m)=(6, 5, 1) we notice that the space probability distribution for a moving particle will move towards two poles of axis z as the relative probability value P increases. Moreover, we discuss the series expansion of the deformed spherical harmonics through the orthogonal and complete spherical harmonics and find that the principal component decreases gradually and other components will increase as the potential parameter b increases.Comment: 28 pages, 6 tables, 1 figure

Ultraquantum magnetoresistance in Kramers Weyl semimetal candidate β\beta-Ag2Se

The topological semimetal $\beta$-Ag2Se features a Kramers Weyl node at the origin in momentum space and a quadruplet of spinless Weyl nodes, which are annihilated by spin-orbit coupling. We show that single crystalline $\beta$-Ag2Se manifests giant Shubnikov-de Haas oscillations in the longitudinal magnetoresistance which stem from a small electron pocket that can be driven beyond the quantum limit by a field less than 9 T. This small electron pocket is a remainder of the spin-orbit annihilatedWeyl nodes and thus encloses a Berry-phase structure. Moreover, we observed a negative longitudinal magnetoresistance when the magnetic field is beyond the quantum limit. Our experimental findings are complemented by thorough theoretical band structure analyses of this Kramers Weyl semimetal candidate, including first-principle calculations and an effective k*p model.Comment: A new version based on arXiv:1502.0232

Erythrocyte–Brain Endothelial Interactions Induce Microglial Responses and Cerebral Microhemorrhages in Vivo

Background Cerebral microhemorrhages (CMH) are associated with stroke, cognitive decline, and normal aging. Our previous study shows that the interaction between oxidatively stressed red blood cells (RBC) and cerebral endothelium may underlie CMH development. However, the real-time examination of altered RBC–brain endothelial interactions in vivo, and their relationship with clearance of stalled RBC, microglial responses, and CMH development, has not been reported. Methods RBC were oxidatively stressed using tert-butylhydroperoxide (t-BHP), fluorescently labeled and injected into adult Tie2-GFP mice. In vivo two-photon imaging and ex vivo confocal microscopy were used to evaluate the temporal profile of RBC–brain endothelial interactions associated with oxidatively stressed RBC. Their relationship with microglial activation and CMH was examined with post-mortem histology. Results Oxidatively stressed RBC stall significantly and rapidly in cerebral vessels in mice, accompanied by decreased blood flow velocity which recovers at 5 days. Post-mortem histology confirms significantly greater RBC–cerebral endothelial interactions and microglial activation at 24 h after t-BHP-treated RBC injection, which persist at 7 days. Furthermore, significant CMH develop in the absence of blood–brain barrier leakage after t-BHP-RBC injection. Conclusions Our in vivo and ex vivo findings show the stalling and clearance of oxidatively stressed RBC in cerebral capillaries, highlighting the significance of microglial responses and altered RBC–brain endothelial interactions in CMH development. Our study provides novel mechanistic insight into CMH associated with pathological conditions with increased RBC–brain endothelial interactions

Anti-inflammatory effects of NaB and NaPc in Acinetobacter baumannii-stimulated THP-1 cells via TLR-2/NF-κB/ROS/NLRP3 pathway

This study evaluated the anti-inflammation effect of the three main short-chain fatty acids (SCFAs) on Acinetobacter baumannii-induced THP-1 cells. The three main SCFAs could inhibit A. baumannii-stimulated THP-1 cell NF-κB pathway activity and the expressions of NLRP3 inflammasome and GSDMD, and increase autophagy. The three main SCFAs, especially the sodium butyrate (NaB), had the effect of down-regulation of ROS and TLR-2 expression in THP-1 cells. NaB and sodium propionate (NaPc), but not sodium acetate (NaAc), dramatically suppressed IL-1β and IFN-γ expression. The results indicated that NaB and NaPc could significantly inhibit the inflammation of THP-1 cells induced by A. baumannii, and the inhibitory effect was in the order of NaB＞NaPc＞NaAC. NaB and NaPc may inhibit inflammation through TLR-2/NF-κB/ROS/NLRP3 signaling pathway

Copy Number Variation of Cytokinin Oxidase Gene Tackx4 Associated with Grain Weight and Chlorophyll Content of Flag Leaf in Common Wheat

Publisher's version/PDFAs the main pigment in photosynthesis, chlorophyll significantly affects grain filling and grain weight of crop. Cytokinin (CTK) can effectively increase chlorophyll content and chloroplast stability, but it is irreversibly inactivated by cytokinin oxidase (CKX). In this study, therefore, twenty-four pairs of primers were designed to identify variations of wheat CKX (Tackx) genes associated with flag leaf chlorophyll content after anthesis, as well as grain weight in 169 recombinant inbred lines (RIL) derived from Triticum aestivum Jing 411 × Hongmangchun 21. Results indicated variation of Tackx4, identified by primer pair T19-20, was proven to significantly associate with chlorophyll content and grain weight in the RIL population. Here, two Tackx4 patterns were identified: one with two co-segregated fragments (Tackx4-1/Tackx4-2) containing 618 bp and 620 bp in size (as in Jing 411), and another with no PCR product. The two genotypes were designated as genotype-A and genotype-B, respectively. Grain weight and leaf chlorophyll content at 5~15 days after anthesis (DAA) were significantly higher in genotype-A lines than those in genotype-B lines. Mapping analysis indicated Tackx4 was closely linked to Xwmc169 on chromosome 3AL, as well as co-segregated with a major quantitative trait locus (QTL) for both grain weight and chlorophyll content of flag leaf at 5~15 DAA. This QTL explained 8.9~22.3% phenotypic variations of the two traits across four cropping seasons. Among 102 wheat varieties, a third genotype of Tackx4 was found and designated as genotype-C, also having two co-segregated fragments, Tackx4-2 and Tackx4-3 (615bp). The sequences of three fragments, Tackx4-1, Tackx4-2, and Tackx4-3, showed high identity (>98%). Therefore, these fragments could be considered as different copies at Tackx4 locus on chromosome 3AL. The effect of copy number variation (CNV) of Tackx4 was further validated. In general, genotype-A contains both significantly higher grain weight and flag leaf chlorophyll content at 5~15 DAA than those in genotype-B and genotype-C, among 102 varieties under various environments.This work was supported by grants from the National Natural Science Foundation of China (31000705), the China Agriculture Research System (CARS-03), the Scientific Research Special Program of Agricultural Commonwealth (201203033-04), Natural Science Foundation of Anhui Province (1508085MC57), the Agriculture Research System of Anhui Province (AHCYTX-02), Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC) and the introduced leading talent research team for Universities in Anhui Province. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

A turn-off fluorescent probe for the detection of Cu2+ based on a tetraphenylethylene-functionalized salicylaldehyde Schiff-base

A non-planar tetraphenylethylene-functionalized salicylaldehyde Schiff-base fluorescent probe (TPE-An-Py) with aggregation-induced enhanced emission (AIEE) characteristics was synthesized via a classical Knoevenagel condensation reaction, and exhibited a high sensitivity towards copper ions in aqueous media with a "turn-off" fluorescence mechanism; the limit of detection is 2.36 × 10-7 mol L-1. Importantly, the coordination mode of the probe towards copper was further evaluated by UV-vis and NMR spectroscopy and a 1:2 stoichiometry was identified. A single crystal X-ray diffraction study confirmed the binding mode. In addition, the AIEE fluorescent probe can be applied to the detection of Cu2+ in practical samples with satisfactory recoveries in a range of 106-111% in lake water and 97-108% in tap water