3,253 research outputs found

    Macroscopic Quantum Tunneling Effect of Z2 Topological Order

    Full text link
    In this paper, macroscopic quantum tunneling (MQT) effect of Z2 topological order in the Wen-Plaquette model is studied. This kind of MQT is characterized by quantum tunneling processes of different virtual quasi-particles moving around a torus. By a high-order degenerate perturbation approach, the effective pseudo-spin models of the degenerate ground states are obtained. From these models, we get the energy splitting of the ground states, of which the results are consistent with those from exact diagonalization methodComment: 25 pages, 14 figures, 4 table

    On the Vertex Operators of the Elliptic Quantum Algebra Uq,p(sl2^)kU_{q,p}(\widehat{sl_2})_{k}}

    Full text link
    A realization of the elliptic quantum algebra Uq,p(sl2^)U_{q,p}(\widehat{sl_2}) for any given level kk is constructed in terms of three free boson fields and their accompanying twisted partners. It can be viewed as the elliptic deformation of Wakimoto realization. Two screening currents are constructed; they commute or anti-commute with Uq,p(sl2^)U_{q,p}(\widehat{sl_2}) modulo total q-differences. The free fields realization for two types vertex operators nominated as the type II and the type IIII vertex operators are presented. The twisted version of the two types vertex operators are also obtained. They all play crucial roles in calculating correlation functions.Comment: 23 page

    Anyonic statistics with continuous variables

    Full text link
    We describe a continuous-variable scheme for simulating the Kitaev lattice model and for detecting statistics of abelian anyons. The corresponding quantum optical implementation is solely based upon Gaussian resource states and Gaussian operations, hence allowing for a highly efficient creation, manipulation, and detection of anyons. This approach extends our understanding of the control and application of anyons and it leads to the possibility for experimental proof-of-principle demonstrations of anyonic statistics using continuous-variable systems.Comment: 5 pages, 2 figures, appear in Phys. Rev.

    Full one-loop electroweak corrections to h0(H0,A0)H±W∓h^0(H^0,A^0) H^\pm W^\mp associated productions at e+e−e^+e^- linear colliders

    Get PDF
    We study the complete one-loop electroweak(EW) corrections to the processes of single charged Higgs boson production associated with a neutral Higgs boson(h0,H0,A0)(h^0,H^0,A^0) and a gauge boson W±W^\pm in the framework of the minimal supersymmetric standard model(MSSM). Numerical results at the SPS1a′{\rm SPS1a'} benchmark point as proposed in the SPA project, are presented for demonstration. We find that for the process e+e−→h0H±W∓e^+e^-\to h^0H^\pm W^\mp the EW relative correction can be either positive or negative and in the range of −15-15%\sim 20% in our chosen parameter space. While for the processes e+e−→H0(A0)H±W∓e^+e^-\to H^0(A^0)H^\pm W^\mp the corrections generally reduce the Born cross sections and the EW relative corrections are typically of order −10−20-10%\sim -20%.Comment: 22 pages, 20 figures, LaTex, to be appeared in PR

    Longitudinal dependence of B and D meson nuclear modifications in heavy-ion collisions at RHIC and the LHC

    Full text link
    It is widely acknowledged that heavy flavor probes are sensitive to the properties of the quark-gluon plasma and are often considered an important tool for the plasma tomography studies. Forward rapidity observables can provide further insight on the dynamics of the medium due to the interplay between the medium size and the differences in the production spectra of heavy quark probes. In this proceedings we present the nuclear modification factor RAAR_\text{AA}'s for B and D mesons, as well as heavy flavor leptons, in the rapidity range −4.0<y<4.0-4.0 < y < 4.0 obtained from relativistic Langevin equation with gluon radiation coupled with a (3+1)-dimensional viscous hydrodynamics medium background. We present comparison with experimental data at mid-rapidity as well as predictions for different rapidity ranges.Comment: 4 pages, 4 figures, contribution to the proceedings of Quark Matter - XXVIII international conference on ultrarelativistic heavy-ion collisions (Wuhan, China, 4-9 November, 2019

    MicroRNA-1 acts as a tumor suppressor microRNA by inhibiting angiogenesis-related growth factors in human gastric cancer

    Get PDF
    Background We recently reported that miR-1 was one of the most significantly downregulated microRNAs in gastric cancer (GC) patients from The Cancer Genome Atlas microRNA sequencing data. Here we aim to elucidate the role of miR-1 in gastric carcinogenesis. Methods We measured miR-1 expression in human GC cell lines and 90 paired primary GC samples, and analyzed the association of its status with clinicopathological features. The effect of miR-1 on GC cells was evaluated by proliferation and migration assay. To identify the target genes of miR-1, bioinformatic analysis and protein array analysis were performed. Moreover, the regulation mechanism of miR-1 with regard to these predicted targets was investigated by quantitative PCR (qPCR), Western blot, ELISA, and endothelial cell tube formation. The putative binding site of miR-1 on target genes was assessed by a reporter assay. Results Expression of miR-1 was obviously decreased in GC cell lines and primary tissues. Patients with low miR-1 expression had significantly shorter overall survival compared with those with high miR-1 expression (P = 0.0027). Overexpression of miR-1 in GC cells inhibited proliferation, migration, and tube formation of endothelial cells by suppressing expression of vascular endothelial growth factor A (VEGF-A) and endothelin 1 (EDN1). Conversely, inhibition of miR-1 with use of antago-miR-1 caused an increase in expression of VEGF-A and EDN1 in nonmalignant GC cells or low-malignancy GC cells. Conclusions MiR-1 acts as a tumor suppressor by inhibiting angiogenesis-related growth factors in human gastric cancer. Downregulated miR-1 not only promotes cellular proliferation and migration of GC cells, but may activates proangiogenesis signaling and stimulates the proliferation and migration of endothelial cells, indicating the possibility of new strategies for GC therapy

    The elliptic quantum algebra Uq,p(slN^)U_{q,p}(\hat{sl_N}) and its vertex operators

    Full text link
    We construct a realization of the elliptic quantum algebra Uq,p(slN^)U_{q,p}(\hat{sl_N}) for any given level kk in terms of free boson fields and their twisted partners. It can be considered as the elliptic deformation of the Wakimoto realization of the quantum affine algebra Uq(slN^)U_{q}(\hat{sl_N}). We also construct a family of screening currents, which commute with the currents of Uq,p(slN^)U_{q,p}(\hat{sl_N}) up to total q-differences. And we give explicit twisted expressions for the type II and the type IIII vertex operators of Uq,p(slN^)U_{q,p}(\hat{sl_N}) by twisting the known results of the type II vertex operators of the quantum affine algebra Uq(slN^)U_{q}(\hat{sl_N}) and the new results of the type IIII vertex operators of Uq(slN^)U_{q}(\hat{sl_N}) we obtained in this paper.Comment: 28 page

    Suppressing nano-scale stick-slip motion by feedback

    Full text link
    When a micro cantilever with a nano-scale tip is manipulated on a substrate with atomic-scale roughness, the periodic lateral frictional force and stochastic fluctuations may induce stick-slip motion of the cantilever tip, which greatly decreases the precision of the nano manipulation. This unwanted motion cannot be reduced by open-loop control especially when there exist parameter uncertainties in the system model, and thus needs to introduce feedback control. However, real-time feedback cannot be realized by the existing virtual reality virtual feedback techniques based on the position sensing capacity of the atomic force microscopy (AFM). To solve this problem, we propose a new method to design real-time feedback control based on the force sensing approach to compensate for the disturbances and thus reduce the stick-slip motion of the cantilever tip. Theoretical analysis and numerical simulations show that the controlled motion of the cantilever tip tracks the desired trajectory with much higher precision. Further investigation shows that our proposal is robust under various parameter uncertainties. Our study opens up new perspectives of real-time nano manipulation.Comment: 8 pages, 10 figure
    • …
    corecore