On the Topological Origin of Entanglement in Ising Spin Glasses

The origin of thermal and quantum entanglement in a class of three-dimensional spin models, at low momenta, is traced to purely topological reasons. The establishment of the result is facilitated by the gauge principle which, when used in conjunction with the duality mapping of the spin models, enables us to recast them as lattice Chern-Simons gauge theories. The thermal and quantum entanglement measures are expressed in terms of the expectation values of Wilson lines, loops, and their generalisations. For continuous spins, these are known to yield the topological invariants of knots and links. For Ising-like models, they are expressible in terms of the topological invariants of three-manifolds obtained from finite group cohomology -- the so-called Dijkgraaf-Witten invariants.Comment: RevTex4, 6 page

Emergence of Artificial Photons in an Optical Lattice

We establish the theoretical feasibility of direct analog simulation of the compact U(1) lattice gauge theories in optical lattices with dipolar bosons. We discuss the realizability of the topological Coulomb phase in extended Bose-Hubbard models in several optical lattice geometries. We predict the testable signatures of this emergent phase in noise correlation measurements, thus suggesting the possible emergence of artificial light in optical lattices.Comment: 4 pages, 2 eps figur

Algebraic spin liquid as the mother of many competing orders

We study the properties of a class of two-dimensional interacting critical states -- dubbed algebraic spin liquids -- that can arise in two-dimensional quantum magnets. A particular example that we focus on is the staggered flux spin liquid, which plays a key role in some theories of underdoped cuprate superconductors. We show that the low-energy theory of such states has much higher symmetry than the underlying microscopic spin system. This symmetry has remarkable consequences, leading in particular to the unification of a number of seemingly unrelated competing orders. The correlations of these orders -- including, in the staggered flux state, the Neel vector and the order parameter for the columnar and box valence-bond solid states -- all exhibit the SAME slow power-law decay. Implications for experiments in the pseudogap regime of the cuprates and for numerical calculations on model systems are discussed.Comment: Minor changes; final published version. 17 pages, 3 figure

Light trap, an effective component of integrated management of Tuta absoluta(Lepidoptera : Gelechiidae) on Tomato

The effectiveness of mass trapping the moths of Tuta absoluta was evaluated using light traps in tomato polyhouse at ICAR-Indian Institute of Horticultural Research, Bengaluru during March - June, 2018. Various colours of light sources were evaluated for their efficacy in attracting the moths. Of different coloured light sources evaluated, yellow and white (bluish) were found relatively effective for attraction of the moths. The efficacy of mass trapping was further evaluated and incandescent yellow bulb of 60 W was found most efficient in attracting both sexes of Tuta moths. Thus light traps can be an effective tool for IPM of this pest on tomato, under polyhouse conditions

Control strategies for seamless transfer between the grid-connected and islanded modes of a microgrid system

Design of control strategies for Distributed generation systems is very important to achieve smoother transition between the grid connected and islanding modes of operation. The transition between these two modes of operation should be seamless, without any severe transients during the changeover. In this paper, two different control strategies namely inverter output current control and indirect grid current control for the seamless transfer between the modes of operation has been explored for the suitability. The design and analysis of the cascaded control loops based on Proportional Integral (PI) controller has been dealt in detail for both inverter output current control and indirect grid current control strategy. Control parameters are designed using the control system toolbox in MATLAB. A 10kW grid connected microgrid system has been designed and simulated in MATLAB/Simulink and the results are presented under grid connected operation, islanding operation and the transition between the modes considering fault condition in the grid side. The simulation studies are carried out using both the control strategies and the results are presented to validate the design methodology

Online access to DRDO periodicals using open source software

Defence Scientific Information and Documentation Centre (DESIDOC) is a nodal centre for information communication and dissemination in the Defence Research & Development Organization (DRDO). As the publication wing of DRDO, DESIDOC brings out regular publications including Defence Science Journal, DESIDOC Bulletin of Information Technology, DRDO Newsletter, DRDO Samachar and Technology Focus. These periodicals cover a wide variety of topics in various subject areas targeting different user communities situated all over India. A pilot project was undertaken with an aim to provide online desktop access to the full text of these periodicals to the users including R&D scientists of more than 50 laboratories and establishments. The project also aimed at facilitating the Publications Division to directly upload the contents to the system. The open source software EPrints is used and customized according to the user requirements particularly on Intranet. Upon successful testing and evaluation, these periodicals will be hosted on Internet allowing subscription, access and downloading by users across the globe. This paper discusses the experience in using EPrints and customization at various levels for DRDO publications and explains various features of the model

Mechanical Characterization of Coir Fiber and Cotton Fiber Reinforced Unsaturated Polyester Composites for Packaging Applications

The aim of this work is to develop a natural fiber composites that can become a substitute for plywood and medium density fiber boards used in packaging application. In this work, the composite was fabricated with randomly oriented chopped coir and cotton fiber reinforced with unsaturated polyester resin. The different types of composite materials were prepared with different quantity of coir fiber and cotton fiber reinforced with unsaturated polyester by using hand lay-up technique. Mechanical properties such as tensile, flexural, impact and hardness strength are evaluated. Scanning Electron Microscope (SEM) was conducted on the fabricated composite to analysis the interfacial properties, internal cracks and internal structure of the fractured surfaces. Based on the results, cotton fiber reinforced with unsaturated polyester has better mechanical properties to be used for packaging applications compared with other combinations of coir/cotton fiber reinforced with unsaturated polyester

Strange metals as ersatz Fermi liquids

A long standing mystery of fundamental importance in correlated electron physics is to understand strange non-Fermi liquid metals that are seen in diverse quantum materials. A striking experimental feature of these metals is a resistivity that is linear in temperature ($T$). In this paper we ask what it takes to obtain such non-Fermi liquid physics down to zero temperature in a translation invariant metal. If in addition the full frequency ($\omega$) dependent conductivity satisfies $\omega/T$ scaling, we argue that the $T$-linear resistivity must come from the intrinsic physics of the low energy fixed point. Combining with earlier arguments that compressible translation invariant metals are `ersatz Fermi liquids' with an infinite number of emergent conserved quantities, we obtain powerful and practical conclusions. We show that there is necessarily a diverging susceptibility for an operator that is odd under inversion/time reversal symmetries, and has zero crystal momentum. We discuss a few other experimental consequences of our arguments, as well as potential loopholes which necessarily imply other exotic phenomena.Comment: 6 pages + 4 pages appendices. v3 various minor correction

A Scheme for Detecting the Sinkhole for Secured WSN

Because of the limited computation capability as well as transmissions being broadcasted in a wireless sensor network (WSN) they are supposed to be more susceptible for attacks related to the security. As present wireless sensor networks have low-power constraints as well as increased complexity, thus for nodes’ performance analysis related to the embedded software and network simulation efficient approaches are required. Additionally, as these networks are used to deal with the sensitive information and operated in the adverse unattended environments, thus, security feature must be added in most of these wireless sensor networks. In this paper a novel scheme for detecting various sinkhole nodes for wireless sensor network (WSN). The results of this proposed scheme show the 1.75% fake positive rate and 96% of detection rate. In comparison to the previous schemes, these aspects are considerably better. In addition to these aspects, our scheme also achieves the communication as well as computational efficiencies. As a result of which, this proposed scheme proved to have better results in many applications.