Magnetic relaxation in hard type-II superconductors

Magnetic relaxation in a type-II superconductor is simulated for a range of temperatures (T) in a simple model of 2D Josephson junction array (JJA) with finite screening. The high-T phase, that is characterised by a single time scale \tau_{\alpha}, crosses over to an intermediate phase at a lower temperature T_{cr} wherein a second time scale \tau_{\beta}<<\tau_{\alpha} emerges. The relaxation in the time window set by \tau_{\beta} follows power law which is attributed to self-organization of the magnetic flux during relaxation. Consequently, for T<T_{cr}, a transition from super-critical (current density J>J_{c}) to sub-critical (J<J_{c}) state separated by an intermediate state with frozen dynamics is observed. Both \tau_{\alpha} and \tau_{\beta} diverges at T_{sc}<T_{cr}, marking the transition into a state with true persistent current.Comment: 7 Pages (in Europhys format, .sty included), 5 Figures. To appear in Europhysics Letter

TinkerCell: Modular CAD Tool for Synthetic Biology

Synthetic biology brings together concepts and techniques from engineering and biology. In this field, computer-aided design (CAD) is necessary in order to bridge the gap between computational modeling and biological data. An application named TinkerCell has been created in order to serve as a CAD tool for synthetic biology. TinkerCell is a visual modeling tool that supports a hierarchy of biological parts. Each part in this hierarchy consists of a set of attributes that define the part, such as sequence or rate constants. Models that are constructed using these parts can be analyzed using various C and Python programs that are hosted by TinkerCell via an extensive C and Python API. TinkerCell supports the notion of a module, which are networks with interfaces. Such modules can be connected to each other, forming larger modular networks. Because TinkerCell associates parameters and equations in a model with their respective part, parts can be loaded from databases along with their parameters and rate equations. The modular network design can be used to exchange modules as well as test the concept of modularity in biological systems. The flexible modeling framework along with the C and Python API allows TinkerCell to serve as a host to numerous third-party algorithms. TinkerCell is a free and open-source project under the Berkeley Software Distribution license. Downloads, documentation, and tutorials are available at www.tinkercell.com.Comment: 23 pages, 20 figure

Haldane Statistics in the Finite Size Entanglement Spectra of Laughlin States

We conjecture that the counting of the levels in the orbital entanglement spectra (OES) of finite-sized Laughlin Fractional Quantum Hall (FQH) droplets at filling $\nu=1/m$ is described by the Haldane statistics of particles in a box of finite size. This principle explains the observed deviations of the OES counting from the edge-mode conformal field theory counting and directly provides us with a topological number of the FQH states inaccessible in the thermodynamic limit- the boson compactification radius. It also suggests that the entanglement gap in the Coulomb spectrum in the conformal limit protects a universal quantity- the statistics of the state. We support our conjecture with ample numerical checks.Comment: 4.1 pages, published versio

Bulk-Edge Correspondence in the Entanglement Spectra

Li and Haldane conjectured and numerically substantiated that the entanglement spectrum of the reduced density matrix of ground-states of time-reversal breaking topological phases (fractional quantum Hall states) contains information about the counting of their edge modes when the ground-state is cut in two spatially distinct regions and one of the regions is traced out. We analytically substantiate this conjecture for a series of FQH states defined as unique zero modes of pseudopotential Hamiltonians by finding a one to one map between the thermodynamic limit counting of two different entanglement spectra: the particle entanglement spectrum, whose counting of eigenvalues for each good quantum number is identical (up to accidental degeneracies) to the counting of bulk quasiholes, and the orbital entanglement spectrum (the Li-Haldane spectrum). As the particle entanglement spectrum is related to bulk quasihole physics and the orbital entanglement spectrum is related to edge physics, our map can be thought of as a mathematically sound microscopic description of bulk-edge correspondence in entanglement spectra. By using a set of clustering operators which have their origin in conformal field theory (CFT) operator expansions, we show that the counting of the orbital entanglement spectrum eigenvalues in the thermodynamic limit must be identical to the counting of quasiholes in the bulk. The latter equals the counting of edge modes at a hard-wall boundary placed on the sample. Moreover, we show this to be true even for CFT states which are likely bulk gapless, such as the Gaffnian wavefunction.Comment: 20 pages, 6 figure

Peak Effect in Superconductors: Absence of Phase Transition and Possibility of Jamming in Vortex Matter

The magnetic field $B$ dependence of the critical current $I_c$ for the vortex phase of a disordered superconductor is studied numerically at zero temperature. The $I_{c}(B)$ increases rapidly near the upper critical field $B_{c2}$ similar to the peak effect (PE) phenomenon observed in many superconductors. The real space configuration across the PE changes continuously from a partially ordered domain (polycrystalline) state into an amorphous state. The topological defect density $n_{d}(B)\sim e^{\alpha B^{k}}$ with $k>1$ for $B\geq 0.4B_{c2}$. There is no evidence of a phase transition in the vicinity of the PE suggesting that an order-disorder transition is not essential for the occurrence of the PE phenomenon. An alternative view is presented wherein the vortex system with high dislocation density undergoes jamming at the onset of the PE.Comment: 8 pages and 5 figure

A relationship between service quality and customer satisfaction in e-banking services- a study with reference to commercial banks in Chennai City

Purpose: This paper's main aim is to validate the service quality dimensions offered by commercial banks in the study area and the relationship between service quality dimensions and customer satisfaction provided by commercial banks.   Theoretical Framework: In India, three categories of commercial banks are the public sector, private sector, and foreign banks. These banks have heavy competition among themselves in maximising their customer base.   Design/Methodology/Approach: The researcher collected 600 responses through convenience sampling. Applied exploratory factor analysis, confirmatory factor analysis, regression analysis and structural equation model to conclude that service quality of electronic banking service is not a unique phenomenon.   Findings: E-Banking depends upon the five essential factors: reliability, safety and security, assurance, technological augmentation, and quickness since the electronic banking services offered by commercial banks are entirely based on the Internet process.   Research, Practical &amp; Social Implications: The study identifies the customer requirements and how commercial banks could satisfy such requirements with their banking strategies. Also, the study identifies whether any demographic difference exists among the customers of commercial banks in perceiving the quality of e-banking services

A Relationship Between Ethnocentrism and Purchase Decision Pattern of Consumer in Chennai City

Purpose: This research aimed to find out what causes consumer ethnocentrism. In addition, the study will look into the relationship between ethnocentrism and consumer purchase patterns in Chennai.   Theoretical Framework: Consumers are increasingly confronted with a wide selection of home and foreign products as marketplaces become more globalised. Consumer ethnocentric attitudes are one factor affecting the purchase of domestic versus international products.   Design/Methodology/Approach: A total of 139 consumers in Chennai were polled in this face-to-face study. Correlation and regression tests were used to analyse the data.   Findings: Consumer ethnocentrism is most strongly predicted by the factor 'prejudice.'   Research, Practical &amp; Social Implications: According to the study, consumer ethnocentrism significantly and positively impacts customers' purchasing decision patterns.   Originality/Value: To develop successful marketing tactics inside and outside national borders, marketers must comprehend consumers' ethnocentric tendencies. The study's findings will also help marketers create and tailor their own strategic initiatives for the home market. The results of this study suggest that customer ethnocentrism and consumer shopping habits in Chennai are related

Characterization of a qubit Hamiltonian using adaptive measurements in a fixed basis

We investigate schemes for Hamiltonian parameter estimation of a two-level system using repeated measurements in a fixed basis. The simplest (Fourier based) schemes yield an estimate with a mean square error (MSE) that decreases at best as a power law ~N^{-2} in the number of measurements N. By contrast, we present numerical simulations indicating that an adaptive Bayesian algorithm, where the time between measurements can be adjusted based on prior measurement results, yields a MSE which appears to scale close to \exp(-0.3 N). That is, measurements in a single fixed basis are sufficient to achieve exponential scaling in N.Comment: 5 pages, 3 figures, 1 table. Published versio