Statistical Properties of E(5) and X(5) Symmetries

We study the energy level statistics of the states in E(5) and X(5) transitional dynamical symmetries. The calculated results indicate that the statistics of E(5) symmetry is regular and follows Poisson statistics, while the statistics of X(5) symmetry involves two maxima in the nearest neighbor level spacing distribution $P(s)$ and the $\Delta_{3}$ statistics follows the GOE statistics. It provides an evidence that the X(5) symmetry is at the critical point exhibiting competing degree of freedom.Comment: 15 pages, 14 figure

Quantum Information Transfer between Topological and Superconducting Qubits

We describe a scheme that enables a strong Jaynes-Cummings coupling between a topological qubit and a superconducting flux qubit. The coupling strength is dependent on the phase difference between two superconductors on a topological insulator and may be expediently controlled by a phase controller. With this coherent coupling and single-qubit rotations arbitrary unitary operations on the two-qubit hybrid system of topological and flux qubits can be performed. Numerical simulations show that quantum state transfer and entanglement distributing between the topological and superconducting flux qubits may be performed with high fidelity.Comment: 5 pages, 3 figure

Electrical Control of Strong Spin-Phonon Coupling in a Carbon Nanotube

We describe an approach to electrically control the strong interaction between a single electron spin and the vibrational motion of a suspended carbon nanotube resonator. The strength of the deflection-induced spin-phonon coupling is dependent on the wavefunction of the electron confined in a lateral carbon nanotube quantum dot. An electrical field along the nanotube shifts the effective center of the quantum dot, leading to the corresponding modification of the spin-phonon strength. Numerical simulations with experimentally reachable parameters show that high fidelity quantum state transfer between mechanical and spin qubits driven by electrical pulses is feasible. Our results form the basis for the fully electrical control of the coherent interconvertion between light and spin qubits and for manufacturing electrically driven quantum information processing systems.Comment: 4pages,3figure

Lie-point symmetries of the Lagrangian system on time scales

This letter investigates the Lie point symmetries and conserved quantities of the Lagrangian systems on time scales, which unify the Lie symmetries of the two cases for the continuous and the discrete Lagrangian systems. By defining the infinitesimal transformations' generators and using the invariance of differential equations under infinitesimal transformations, the determining equations of the Lie symmetries on time scales are established. Then the structure equations and the form of conserved quantities with delta derivatives are obtained. The letter also gives brief discussion on the Lie symmetries for the discrete systems. Finally, several examples are designed to illustrate these results.Comment: 14 pages,0 figure

Two-particle interferometry for the sources undergoing first-order QCD phase transition in high energy heavy ion collisions

We investigate the two-particle interferometry for the particle-emitting sources which undergo the first-order phase transition from the quark-gluon plasma with a finite baryon chemical potential to hadron resonance gas. The effects of source expansion, lifetime, and particle absorption on the transverse interferometry radii $R_{\rm out}$ and $R_{\rm side}$ are examined. We find that the emission durations of the particles become large when the system is initially located at the boundary between the mixed phase and the quark-gluon plasma. In this case, the difference between the radii $R_{\rm out}$ and $R_{\rm side}$ increases with the transverse momentum of the particle pair significantly. The ratio of $\sqrt{R_{\rm out}^2 -R_{\rm side}^2}$ to the transverse velocity of the pair is an observable for the enhancement of the emission duration.Comment: 10 pages, 12 figures. arXiv admin note: text overlap with arXiv:0811.475

Pseudo-rapidity Distributions of Charged Hadrons in pp and pA Collisions at the LHC

In the framework of Color Glass Condensate, the pseudo-rapidity distributions of charged hadrons in pp and pA collisions at the LHC are studied with the UGD function from the GBW model. With a $\chi^{2}$ analysis of the CMS data in pp collisions at $\sqrt{s}=0.9,~2.36,~7$ TeV, the normalization factor is obtained and the theoretical results are in good agreement with the perimental data. Then, considering the influence of nucleon hard partons distribution on the number of participants in pA collisions by a Glauber Monte Carlo method, we give the predictive results for the multiplicity distributions in p+Pb collisions at $\sqrt{s}=4.4$ TeV.Comment: 9 pages, 3 figure

A holographic model of d-wave superconductor vortices with Lifshitz scaling

We study analytically the $d$-wave holographic superconductors with Lifshitz scaling in the presence of external magnetic field. The vortex lattice solutions of the model have also been obtained with different Lifshitz scaling. Our results imply that holographic $d$-wave superconductor is indeed a type II one even for different Lifshitz scaling. This is the same as the conventional $d$-wave superconductors in the Ginzburg-Landau theory. Our results also indicate that the dynamical exponent $z$ has no effect to the shape of the vortex lattice even after higher order corrections (away from the phase transition point $B_c$) are included. However, it has effects on the upper critical magnetic field $B_{c_2}$ through the fact that a larger $z$ results in a smaller $B_{c_2}$ and therefore influences the size (characterized by $r_0\equiv 1/\sqrt{B_{c_2}}$) of the vortex lattices. Furthermore, close comparisons between our results and those of the Ginzburg-Landau theory reveal the fact that the upper critical magnetic field $B_{c_2}$ is inversely proportional to the square of the superconducting coherence length $\xi$, regardless of the anisotropy between space and time.Comment: 21 pages, 6 figures. One subsection added, typos corrected, references added. arXiv admin note: substantial text overlap with arXiv:1311.6260, arXiv:1209.4272, arXiv:1007.4151 by other author

Hierarchical modularity of nested bow-ties in metabolic networks

The exploration of the structural topology and the organizing principles of genome-based large-scale metabolic networks is essential for studying possible relations between structure and functionality of metabolic networks. Topological analysis of graph models has often been applied to study the structural characteristics of complex metabolic networks.In this work, metabolic networks of 75 organisms were investigated from a topological point of view. Network decomposition of three microbes (Escherichia coli, Aeropyrum pernix and Saccharomyces cerevisiae) shows that almost all of the sub-networks exhibit a highly modularized bow-tie topological pattern similar to that of the global metabolic networks. Moreover, these small bow-ties are hierarchically nested into larger ones and collectively integrated into a large metabolic network, and important features of this modularity are not observed in the random shuffled network. In addition, such a bow-tie pattern appears to be present in certain chemically isolated functional modules and spatially separated modules including carbohydrate metabolism, cytosol and mitochondrion respectively. The highly modularized bow-tie pattern is present at different levels and scales, and in different chemical and spatial modules of metabolic networks, which is likely the result of the evolutionary process rather than a random accident. Identification and analysis of such a pattern is helpful for understanding the design principles and facilitate the modelling of metabolic networks.Comment: 26 pages, 9 figure

Bow-tie topological features of metabolic networks and the functional significance

Exploring the structural topology of genome-based large-scale metabolic network is essential for investigating possible relations between structure and functionality. Visualization would be helpful for obtaining immediate information about structural organization. In this work, metabolic networks of 75 organisms were investigated from a topological point of view. A spread bow-tie model was proposed to give a clear visualization of the bow-tie structure for metabolic networks. The revealed topological pattern helps to design more efficient algorithm specifically for metabolic networks. This coarse-grained graph also visualizes the vulnerable connections in the network, and thus could have important implication for disease studies and drug target identifications. In addition, analysis on the reciprocal links and main cores in the GSC part of bow-tie also reveals that the bow-tie structure of metabolic networks has its own intrinsic and significant features which are significantly different from those of random networks.Comment: 15 pages, 5 figure

Strong Coupling between a Topological Qubit and a Nanomechanical Resonator

We describe a scheme that enables a strong coherent coupling between a topological qubit and the quantized motion of a magnetized nanomechanical resonator. This coupling is achieved by attaching an array of magnetic tips to a namomechanical resonator under a quantum phase controller which coherently controls the energy gap of a topological qubit. Combined with single-qubit rotations the strong coupling enables arbitrary unitary transformations on the hybrid system of topological and mechanical qubits and may pave the way for the quantum information transfer between topological and optical qubits. Numerical simulations show that quantum state transfer and entanglement distributing between the topological and mechanical qubits may be accomplished with high fidelity.Comment: 5 pages, 3 figures. arXiv admin note: text overlap with arXiv:1301.453