Effect of laser on the bound magnetic polaron in a semimagnetic quantum wire

In the present investigation binding energy of the laser dressed hydrogenic donor in a Semi magnetic Quantum Wire like Cd1 – xMnx2Te/Cd1 – x1Mnx1Te/Cd1 – x2Mnx2Te and spin polaronic shift has been computed for various magnetic and laser fields within the effective mass approximation in the finite barrier model using variational method. The results are presented and discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2790

Post curing of Hansa-3 (VT- HNW) Components

This report contains the detads of post curing of Hansa-3 (VT- HNW) all composite airframe components provided byC-CADD, carried out using an in-house designed and fabricated large hot air oven (17mts x 2.0mts x 2.0mts). It details an optimum post cure cycle implemented, the temperature accuracy's, the various innovative approaches adapted to ensure the safety of the full scale components undergoing post cure in the oven. All the Hansa-3 (VT-HNW) airframe composite components post cured as per the standard optimum post cure cycle and the oven temperature monitored throughout around f 3degree C to ensure uniform post curing of components

Limits of quantum speedup in photosynthetic light harvesting

It has been suggested that excitation transport in photosynthetic light harvesting complexes features speedups analogous to those found in quantum algorithms. Here we compare the dynamics in these light harvesting systems to the dynamics of quantum walks, in order to elucidate the limits of such quantum speedups. For the Fenna-Matthews-Olson (FMO) complex of green sulfur bacteria, we show that while there is indeed speedup at short times, this is short lived (70 fs) despite longer lived (ps) quantum coherence. Remarkably, this time scale is independent of the details of the decoherence model. More generally, we show that the distinguishing features of light-harvesting complexes not only limit the extent of quantum speedup but also reduce rates of diffusive transport. These results suggest that quantum coherent effects in biological systems are optimized for efficiency or robustness rather than the more elusive goal of quantum speedup.Comment: 9 pages, 6 figures. To appear in New Journal Physics, special issue on "Quantum Effects and Noise in Biomolecules." Updated to accepted versio

A High Galactic Latitude HI 21cm-line Absorption Survey using the GMRT: II. Results and Interpretation

We have carried out a sensitive high-latitude (|b| > 15deg.) HI 21cm-line absorption survey towards 102 sources using the GMRT. With a 3-sigma detection limit in optical depth of ~0.01, this is the most sensitive HI absorption survey. We detected 126 absorption features most of which also have corresponding HI emission features in the Leiden Dwingeloo Survey of Galactic neutral Hydrogen. The histogram of random velocities of the absorption features is well-fit by two Gaussians centered at V(lsr) ~ 0 km/s with velocity dispersions of 7.6 +/- 0.3 km/s and 21 +/- 4 km/s respectively. About 20% of the HI absorption features form the larger velocity dispersion component. The HI absorption features forming the narrow Gaussian have a mean optical depth of 0.20 +/- 0.19, a mean HI column density of (1.46 +/- 1.03) X 10^{20} cm^{-2}, and a mean spin temperature of 121 +/- 69 K. These HI concentrations can be identified with the standard HI clouds in the cold neutral medium of the Galaxy. The HI absorption features forming the wider Gaussian have a mean optical depth of 0.04 +/- 0.02, a mean HI column density of (4.3 +/- 3.4) X 10^{19} cm^{-2}, and a mean spin temperature of 125 +/- 82 K. The HI column densities of these fast clouds decrease with their increasing random velocities. These fast clouds can be identified with a population of clouds detected so far only in optical absorption and in HI emission lines with a similar velocity dispersion. This population of fast clouds is likely to be in the lower Galactic Halo.Comment: 19 pages, 19 figures. Accepted for publication in Journal of Astrophysics & Astronom

Continuous joint measurement and entanglement of qubits in remote cavities

We present a first-principles theoretical analysis of the entanglement of two superconducting qubits in spatially separated microwave cavities by a sequential (cascaded) probe of the two cavities with a coherent mode, that provides a full characterization of both the continuous measurement induced dynamics and the entanglement generation. We use the SLH formalism to derive the full quantum master equation for the coupled qubits and cavities system, within the rotating wave and dispersive approximations, and conditioned equations for the cavity fields. We then develop effective stochastic master equations for the dynamics of the qubit system in both a polaronic reference frame and a reduced representation within the laboratory frame. We compare simulations with and analyze tradeoffs between these two representations, including the onset of a non-Markovian regime for simulations in the reduced representation. We provide conditions for ensuring persistence of entanglement and show that using shaped pulses enables these conditions to be met at all times under general experimental conditions. The resulting entanglement is shown to be robust with respect to measurement imperfections and loss channels. We also study the effects of qubit driving and relaxation dynamics during a weak measurement, as a prelude to modeling measurement-based feedback control in this cascaded system.Comment: 17 pages, 8 figures. Published versio