Hybrid solid state qubits: the powerful role of electron spins

We review progress on the use of electron spins to store and process quantum information, with particular focus on the ability of the electron spin to interact with multiple quantum degrees of freedom. We examine the benefits of hybrid quantum bits (qubits) in the solid state that are based on coupling electron spins to nuclear spin, electron charge, optical photons, and superconducting qubits. These benefits include the coherent storage of qubits for times exceeding seconds, fast qubit manipulation, single qubit measurement, and scalable methods for entangling spatially separated matter-based qubits. In this way, the key strengths of different physical qubit implementations are brought together, laying the foundation for practical solid-state quantum technologies.Comment: 54 pages, 7 figure

Turbulent channel flow near maximum drag reduction: simulations, experiments and mechanisms

It is well known that the drag in a turbulent flow of a polymer solution is significantly reduced compared to Newtonian flow. Here we consider this phenomenon by means of a direct numerical simulation of a turbulent channel flow. The polymers are modelled as elastic dumbbells using the FENE-P model. In the computations the polymer model is solved simultaneously with the flow equations, i.e. the polymers are deformed by the flow and in their turn influence the flow structures by exerting a polymer stress. We have studied the results of varying the polymer parameters, such as the maximum extension, the elasticity and the concentration. For the case of highly extensible polymers the results of our simulations are very close to the maximum drag reduction or Virk (1975) asymptote. Our simulation results show that at approximately maximum drag reduction the slope of the mean velocity profile is increased compared to the standard logarithmic profile in turbulent wall flows. For the r.m.s. of the streamwise velocity fluctuations we find initially an increase in magnitude which near maximum drag reduction changes to a decrease. For the velocity fluctuations in the spanwise and wall-normal directions we find a continuous decrease as a function of drag reduction. The Reynolds shear stress is strongly reduced, especially near the wall, and this is compensated by a polymer stress, which at maximum drag reduction amounts to about 40% of the total stress. These results have been compared with LDV experiments of Ptasinski et al. (2001) and the agreement, both qualitatively and quantitatively, is in most cases very good. In addition we have performed an analysis of the turbulent kinetic energy budgets. The main result is a reduction of energy transfer from the streamwise direction, where the production of turbulent kinetic energy takes place, to the other directions. A substantial part of the energy production by the mean flow is transferred directly into elastic energy of the polymers. The turbulent velocity fluctuations also contribute energy to the polymers. The elastic energy of the polymers is subsequently dissipated by polymer relaxation. We have also computed the various contributions to the pressure fluctuations and identified how these change as a function of drag reduction. Finally, we discuss some cross-correlations and various length scales. These simulation results are explained here by two mechanisms. First, as suggested by Lumley (1969) the polymers damp the cross-stream or wall-normal velocity fluctuations and suppress the bursting in the buffer layer. Secondly, the ‘shear sheltering’ mechanism acts to amplify the streamwise fluctuations in the thickened buffer layer, while reducing and decoupling the motions within and above this layer. The expression for the substantial reduction in the wall drag derived by considering the long time scales of the nonlinear fluctuations of this damped shear layer, is shown to be consistent with the experimental data of Virk et al. (1967) and Virk (1975)

A One-Field Monolithic Fictitious Domain Method for Fluid-Structure Interactions

In this article, we present a one- eld monolithic fictitious domain (FD) method for simulation of general fluid-structure interactions (FSI). "One-fi eld" means only one velocity field is solved in the whole domain, based upon the use of an appropriate L2 projection. "Monolithic" means the fluid and solid equations are solved synchronously (rather than sequentially). We argue that the proposed method has the same generality and robustness as FD methods with distributed Lagrange multiplier (DLM) but is signi ficantly more computationally e fficient (because of one-fi eld) whilst being very straightforward to implement. The method is described in detail, followed by the presentation of multiple computational examples in order to validate it across a wide range of fluid and solid parameters and interactions

A Cache-Aware Approach to Domain Decomposition for Stencil-Based Codes

Partial Differential Equations (PDEs) lie at the heart of numerous scientific simulations depicting physical phenomena. The parallelization of such simulations introduces additional performance penalties in the form of local and global synchronization among cooperating processes. Domain decomposition partitions the largest shareable data structures into sub-domains and attempts to achieve perfect load balance and minimal communication. Up to now research efforts to optimize spatial and temporal cache reuse for stencil-based PDE discretizations (e.g. finite difference and finite element) have considered sub-domain operations after the domain decomposition has been determined. We derive a cache-oblivious heuristic that minimizes cache misses at the sub-domain level through a quasi-cache-directed analysis to predict families of high performance domain decompositions in structured 3-D grids. To the best of our knowledge this is the first work to optimize domain decompositions by analyzing cache misses - thus connecting single core parameters (i.e. cache-misses) to true multicore parameters (i.e. domain decomposition). We analyze the trade-offs in decreasing cache-misses through such decompositions and increasing the dynamic bandwidth-per-core. The limitation of our work is that currently, it is applicable only to structured 3-D grids with cuts parallel to the Cartesian Axes. We emphasize and conclude that there is an imperative need to re-think domain decompositions in this constantly evolving multicore era

An efficient numerical algorithm for a multiphase tumour model

This paper is concerned with the development and application of optimally efficient numerical methods for the simulation of vascular tumour growth. This model used involves the flow and interaction of four different, but coupled, phases which are each treated as incompressible fluids, Hubbard and Byrne (2013). A finite volume scheme is used to approximate mass conservation, with conforming finite element schemes to approximate momentum conservation and an associated equation. The principal contribution of this paper is the development of a novel block preconditioner for solving the linear systems arising from the discrete momentum equations at each time step. In particular, the preconditioned system has both a solution time and a memory requirement that is shown to scale almost linearly with the problem size

Indigenous Traditional Knowledge and Usage of Folk Bio-Medicines among Rongmei Tribe of Tamenglong District of Manipur, India

Background: Rongmei tribe (Kooki), are inhabitant of the Charoi Chagotlong village, Tupul, Tamenglong district of Manipur have the traditional knowledge of folk bio-medicine based on diverse plant species for the prevention and cure of certain chronic diseases. The aim of this study was to document and preserve the indigenous knowledge of the Rongmei tribe on folk medicines.Material and methods: The present work was based on methodical field survey conducted between 2010, to 2013. Local people of within 30-70 age groups of both sexes were interviewed and a group discussion (using a structured interview schedule), was held to know about the type of plant parts used in folk bio-medicines, and their mode of use. The interviewers were drawn from a wide array of disciplines (Vendors, Farmers club, NGO’s, scientific societies, etc.), to obtain maximum information in relation to folk bio-medicine.Results: A total of 60 species belonging to 36 different families (ranging from gymnosperm to angiosperm with medicinal benefits), were discussed briefly with significant emphasis on their local name, scientific name, family, parts used; they claimed to cure various ailments from these plants in this mode of folk bio-medicine. The different plant parts used were leaves, fruits, bulbs, bark, roots, seeds, tuber, trunk, flower, shoot, whole plant, rhizome, stem, wood and berries. Based on a life form of the reported plants comprise herbs, shrubs, trees, grasses, bulb, vine, climber, tuber and succulent.Conclusion: Efforts should be made to promote the use of traditional biomedicines within rural communities to preserve the traditional knowledge.Keywords: Biomedicinal plants, Manipur, Rongmei trib

Development of a Bait System for the Pharaoh’s Ant, Monomorium Pharaonis L. (Hymenoptera: Formicidae)

The infestation of the Pharaoh’s ant, Monomorium pharaonis L. is widespread and, sometimes, very serious in homes, hospitals, restaurants, factories, etc. People are helpless because effective baited traps are not available locally, and little has been done locally to develop effective control strategies for these ants. The study aimed at developing an appropriate bait system from local materials for the control of the Pharaoh’s ant. Nine baits and three insecticides were evaluated in the laboratory and field situations. Groundnut cake, dry fish and granulated sugar were the most attractive baits. Rimon (a Benzoylphenyl urea), an insect growth regulator, was the most promising insecticide for incorporation into the bait system. It is, therefore, recommended that a bait system, containing groundnut cake, sugar and dry fish, mixed with 1% Rimon, be evaluated for Pharaoh’s ant control

Response of Laser-Induced Thermal Lens Effect at Solid Surface

Recently Kuo et al. [1,2] and Satio et al.[3] presented the surface-thermal lens (STL) technique, this novel photothermal deformation technique has attracted great attention because it is a highly sensitive, noncontact and nondestructive measurement[4–6]. In this technique, a modulated pump beam is focused on the sample surface to produce the surface deformation and a cw probe beam is incident at the deformation region. Differing from the conventional photothermal deformation techniques, the spot size of the probe beam at the sample surface is much larger than the pump beam one. Then the probe beam reflected from the surface produces a diffraction pattern at the detection plane. More recently, STL technique has been successfully applied to study the temperature dependence of the thermal conductivity of semiconductor materials[5], weak absorption of optical thin films[6] and characterization of the solid materials[7,8]. However, the mechanism of STL phenomena has not been completely understood. Most theoretical models took no account of the influence of the air-thermal lens (ATL), although some experiment showed that the air significantly affected the detected diffraction pattern[2]. In addition, it is necessary to characterize frequency responses of signals because the response is used to determine the thermal property of the solid materials[5]

Screening of Different Tomato Varieties in Saline Areas of Bangladesh

A field study was conducted to screen out a number of Bangladeshi Tomato (Lycopersicon esculentum L.) varieties for salinity tolerance. Three levels of salinity were 2.0-4.0 dS m-1, 4.1-8.0 dS m-1 and 8.1-12.0 dS m-1. Significant varietal and or salinity treatment effects were registered on plant height, leaf area, plant growth, yield, dry matter plant-1, Na+ and Claccumulation in tomato tissues. Variety BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2 consistently showed superior biological activity at moderate salinity (4.1-8.0 dS m-1), based on dry matter biomass production thus displaying relatively greater adaptation to salinity. Under saline condition, all plant parameters of tomato varieties were reduced compared to the control except number of fruits of BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2. Thus, BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2 can be regarded as a breeding material for development of new tomato varieties for tolerance to salinity in saline areas of Bangladesh. DOI: http://dx.doi.org/10.3329/ijarit.v2i1.13989 Int. J. Agril. Res. Innov. & Tech. 2 (1): 13-18, June, 201