Universal Quantum Computation in a Neutral Atom Decoherence Free Subspace

In this paper, we propose a way to achieve protected universal computation in a neutral atom quantum computer subject to collective dephasing. Our proposal relies on the existence of a Decoherence Free Subspace (DFS), resulting from symmetry properties of the errors. After briefly describing the physical system and the error model considered, we show how to encode information into the DFS and build a complete set of safe universal gates. Finally, we provide numerical simulations for the fidelity of the different gates in the presence of time-dependent phase errors and discuss their performance and practical feasibility.Comment: 7 pages, 8 figure

Valley Splitting Theory of SiGe/Si/SiGe Quantum Wells

We present an effective mass theory for SiGe/Si/SiGe quantum wells, with an emphasis on calculating the valley splitting. The theory introduces a valley coupling parameter, $v_v$, which encapsulates the physics of the quantum well interface. The new effective mass parameter is computed by means of a tight binding theory. The resulting formalism provides rather simple analytical results for several geometries of interest, including a finite square well, a quantum well in an electric field, and a modulation doped two-dimensional electron gas. Of particular importance is the problem of a quantum well in a magnetic field, grown on a miscut substrate. The latter may pose a numerical challenge for atomistic techniques like tight-binding, because of its two-dimensional nature. In the effective mass theory, however, the results are straightforward and analytical. We compare our effective mass results with those of the tight binding theory, obtaining excellent agreement.Comment: 13 pages, 7 figures. Version submitted to PR

NEW INITIATIVE OF UNMANNED AERIAL VEHICLE (UAV) EMERGING TECHNOLOGY APPLICATIONS IN NORTH EAST FOR CAPACITY BUILDING AND OUTREACH ACTIVITIES OF NORTH EASTERN SPACE APPLICATIONS CENTRE

Unmanned Aerial Vehicle (UAV) technology is revolutionizing and acting as an alternative for many of remote sensing applications, particularly for very high resolution satellite requirements, considering easy of flying in the areas of persistent cloud cover like North East. According to top market reports, UAV business is growing at very fast rate. It is valued at USD 18.14 Billion in 2017 and is projected to reach USD 52.30 Billion by 2025, at a CAGR of 14.15% from 2018 to 2025.North Eastern Space Applications Centre, Umiam, Shillong, Meghalaya, which is responsible for promoting space technology tools for governance and development activities; has taken up a lead role in initiating use of Unmanned Aerial Vehicle for large number of applications such as natural resources management, infrastructure development, disaster response and rescue, project monitoring, research and development etc. Capacity building, training and outreach are important activities taken up by NESAC for promoting use of UAV remote sensing at central/state/academic/research institutions and individual level. As part of capacity building, NESAC has successfully organized two 2 weeks training program for UAV Remote sensing & Applications for the participants all over the country. NESAC has also organised 1 week training programs for officials from State Remote Sensing Centres of North Eastern Region and North Eastern Council. More than 100 participants have been trained from different part of the country. The focus of the training was to include all aspects of UAV Remote Sensing applications. The details of course curriculum are: basic concepts of UAV, building of UAVs, UAV flight simulation, flight planning, UAV data processing, generation of DSM/DTM/Orthomosaic, use of UAV data for different applications in the field of Agriculture, Disaster management, Forestry, Infrastructure planning, construction monitoring etc. Pilot project is also incorporated as part of the training. Apart from training programs at NESAC, large numbers of application projects (&gt;&thinsp;60&thinsp;nos.) have been successfully completed. Outreach activities are also carried out which includes exhibiting UAVs at seminars, demonstration to large no. of students, showcasing UAV capabilities at disaster drills carried out by State Disaster Management Authority (SDMA) etc. The new initiatives of UAV convinced all concerned at taking up UAV RS applications for governance and developmental activities. The full paper will discuss all the aspects of UAV technology and applications.</p

Spectroscopic Identification of Active Sites of Oxygen-Doped Carbon for Selective Oxygen Reduction to Hydrogen Peroxide

The electrochemical synthesis of hydrogen peroxide (H2O2) via a two-electron (2e-) oxygen reduction reaction (ORR) process provides a promising alternative to replace the energy- intensive anthraquinone process. Herein, we develop a facile template-protected strategy to synthesize a highly active quinone- rich porous carbon catalyst for H2O2 electrochemical production. The optimized PCC900 material exhibits remarkable activity and selectivity, of which the onset potential reaches 0.83 V vs. reversible hydrogen electrode in 0.1 M KOH and the H2O2 selectivity is over 95 % in a wide potential range. Comprehensive synchrotron-based near-edge X-ray absorption fine structure (NEXAFS) spectroscopy combined with electrocatalytic characterizations reveals the positive correlation between quinone content and 2e- ORR performance. The effectiveness of chair-form quinone groups as the most efficient active sites is highlighted by the molecule-mimic strategy and theoretical analysi

Grey number based methodology for non-homogeneous preference elicitation in fuzzy risk analysis management

The significantly increase in the number of vehicles have become a major problem, that cause enormous problems such as congestion, pollution, wastage of money and time. Therefore, the simulating and optimizing traffic control algorithms are needed to accommodate the demand in order to solve traffic congestion problems. Predicting effective and optimal green time taken for the intersections will help minimizing the traffic congestion henceforth reducing the waiting time. In this study, fuzzy logic is used to find optimal traffic waiting time. The method determines the effective and optimal traffic signal timing that suits different traffic densities. In this case, the study has considered a four-way intersection. The results indicate that different road intersections require different effective and optimal of green time to reduce traffic congestion. The higher the number of cars at the intersection, the effective green time will be longer rather than the lesser number of cars. The flexibility feature of the fuzzy logic will provide suitable optimal green time for the intersection, which is cordially benefit the users. It is worth mentioning that fuzzy logic traffic lights controller performed better than the fixed-time controller due to its flexibility and the capability in reducing the waiting time

Biodiversity of Wild Silk Moths in Nagaland

Volume: 106Start Page: 112End Page: 11

Aerosol characteristics in north-east India using ARFINET spectral optical depth measurements

Four years (2010–2014) of spectral aerosol optical depth (AOD) data from 4 Indian Space Research Organisation's ARFINET (Aerosol Radiative Forcing over India) stations (Shillong, Agartala, Imphal and Dibrugarh) in the North-Eastern Region (NER) of India (lying between 22–30°N and 89–98°E) are synthesized to evolve a regional aerosol representation, for the first time. Results show that the columnar AOD (an indicator of the column abundance of aerosols) is highest at Agartala (0.80 ± 0.24) in the west and lowest at Imphal (0.59±0.23) in the east in the pre-monsoon season due to intense anthropogenic bio-mass burning in this region aided by long-range transport from the high aerosol laden regions of the Indo-Gangetic Plains (IGP), polluted Bangladesh and Bay of Bengal. In addition to local biogenic aerosols and pollutants emitted from brick kilns, oil/gas fields, household bio-fuel/fossil-fuel, vehicles, industries. Aerosol distribution and climatic impacts show a west to east gradient within the NER. For example, the climatological mean AODs are 0.67±0.26, 0.52±0.14, 0.40±0.17 and 0.41±0.23 respectively in Agartala, Shillong, Imphal and Dibrugarh which are geographically located from west to east within the NER. The average aerosol burden in NER ranks second highest with climatological mean AOD 0.49±0.2 next to the Indo-Gangetic Plains where the climatological mean AOD is 0.64±0.2 followed by the South and South-East Asia region. Elevated aerosol layers are observed over the eastern most stations Dibrugarh and Imphal, while at the western stations the concentrations are high near the surface. The climate implications of aerosols are evaluated in terms of aerosol radiative forcing (ARF) and consequent heating of the atmosphere in the region which follows AOD and exhibit high values in pre-monsoon season at all the locations except in Agartala. The highest ARF in the atmosphere occurs in the pre-monsoon season ranging from 48.6 Wm−2 in Agartala to 25.1 Wm−2 in Imphal. Winter radiative forcing follows that in pre-monsoon season at these locations. The heating rate is high at 1.2 K day−1 and 1.0 K day−1 over Shillong and Dibrugarh respectively in this season. However, Agartala experiences higher surface forcing (−56.5 Wm−2) and consequent larger heating of the atmosphere of 1.6 K day−1 in winter