Entanglement dynamics following a sudden quench: an exact solution

We present an exact and fully analytical treatment of the entanglement dynamics for an isolated system of $N$ coupled oscillators following a sudden quench of the system parameters. The system is analyzed using the solutions of the time dependent Schrodinger's equation, which are obtained by solving the corresponding nonlinear Ermakov equations. The entanglement entropies exhibit a multi-oscillatory behaviour, where the number of dynamically generated time scales increases with $N$. The harmonic chains exhibit entanglement revival and for larger values of $N (> 10)$, we find near-critical logarithmic scaling for the entanglement entropy, which is modulated by a time dependent factor. The $N=2$ case is equivalent to the two site Bose-Hubbard model in the tunneling regime, which is amenable to empirical realization in cold atom systems.Comment: Figure for large N added, discussion related with near critical scaling behavior adde

E-government Services Adoption and Interdependence: Granger Causality Analysis

Adoption of e-government services varies across the different categories of services: government to citizen services, utility services, commercial services, informational services, social benefit services and mobile based services. Faced with constraint of resources, policy makers devising strategies for better adoption of these services face the challenge of prioritizing among these categories of services. This paper attempts to address this challenge by showing the applicability of Granger causality analysis in studying the causation analysis between the categories of e-government services. We prove the applicability of Granger causality analysis in understanding the independence between e-government service categories by analyzing real transactions data of six categories of e-government services in India. Our analysis shows that the growth of inquiry services in positively impacting the growth of government to citizen transactions is statistically significant. Besides this, both utility services and mobile based services show significant bi-directional Granger causality with government to citizen services. We also discuss policy implications of our analysis

Moisture content investigation in the soil samples using microwave dielectric constant measurement method

The microwaves of typical frequency ranges of 3 GHz to 30 GHz have been in use for remote sensing applications which are progressing rapidly. The microwaves can sense existing moisture in any material that absorbs moisture such as soil or vegetation. In case of soils which may be comprised of variable mix proportionate of solids, liquids or gases and distinct textures subjected to the associated size and the arrangements of soil particles. Hence, the moisture absorption by a specific type of soil used to be different. The inherent physical and electrical properties such as color, texture, grains, dielectric constant, conductivity or permeability, etc. differentiate various soils. In this work, authors present soil moisture measurement by simple estimation of emissivity i.e. the ratio of energy radiated by an object to absorbing the body of same physical temperature. A strategic method of measuring dielectric constant using a microwave signal is used in this research work. The measurement of the dielectric constant of the soils collected from the specific regions and analysis of results has been reported. The proposed method is less complex and can further be used for the identification of soil moisture and agricultural applications

Sunburst quantum Ising model under interaction quench: entanglement and role of initial state coherence

We study the non-equilibrium dynamics of an isolated bipartite quantum system, the sunburst quantum Ising model, under interaction quench. The pre-quench limit of this model is two non-interacting integrable systems, namely a transverse ising chain and finite number of isolated qubits. As a function of interaction strength, the spectral fluctuation property goes from Poisson to Wigner-Dyson statistics. We chose entanglement entropy as a probe to study the approach to thermalization or lack of it in post-quench dynamics. In the near-integrable limit, as expected, the linear entropy displays oscillatory behavior while in the chaotic limit, it saturates. Along with the chaotic nature of the time evolution generator, we show the importance of the role played by the coherence of the initial state in deciding the nature of thermalization. We further show that these findings are general by replacing the Ising ring with a disordered $XXZ$ model with disorder strength putting it in the many-body localized phase

Social Participation among the Elderly: Moderated Mediation Model of Information and Communication Technology (ICT)

Researchers have identified social participation for the elderly as a salient activity that benefits their wellbeing. Along that vein, prior studies have reported that ICT use increases the extent to which the elderly participate socially with one another. However, the literature remains silent on the mechanisms by which ICT use leads to social participation. In this paper, we draw on two prominent IS theories, actor-network theory (ANT) and activity theory (AT), to develop a conceptual framework by incorporating four social participation-oriented factors: ICT use, social participation, social isolation, and loneliness. We used a quantitative approach based on the cross-sectional survey to collect data from 240 elderly people. We analyzed the data using structural equation modeling based on SmartPLS 3.0. We found that the size of the social network constituted the critical factor in the association between ICT use and social participation. The outcome of the model suggests that ICT use does not impact the social participation directly. Rather, social isolation (absence of social network) mediates the relationship between the ICT use and social participation. Additionally, loneliness, one of the commonly observed psychological states in the elderly, weakens the influence of ICT use on social isolation. Our research advances our theoretical understanding about social participation among seniors and helps governments and businesses prepare ICT plans for the elderly appropriately