Chemical potential in disordered organic materials

Charge carrier mobility in disordered organic materials is being actively studied, motivated by several applications such as organic light emitting diodes and organic field-effect transistors. It is known that the mobility in disordered organic materials depends on the chemical potential which in turn depends on the carrier concentration. However, the functional dependence of chemical potential on the carrier concentration is not known. In this study, we focus on the chemical potential in organic materials with Gaussian disorder. We identify three cases of non-degenerate, degenerate and saturated regimes. In each regime we calculate analytically the chemical potential as a function of the carrier concentration and the energetic disorder from the first principles.Comment: 5 pages, 3 figure

Revelation of double magicity in N=Z nuclei in the rp-process region

In rapid-proton capture (rp-process), N=Z nuclei above Ni are understood to act as waiting-point nuclei. The N=Z nuclei 68Se, 72Kr, 76Sr and 80Zr among others are known to give rise to a large-energy x-ray flux and peaks in abundances of these nuclei synthesized in the astrophysical rp-process. Investigating the experimental isotope shifts in Kr isotopes near the proton drip-line within the framework of the deformed Relativistic Hartree-Bogoliubov theory, we have discovered that N=Z rp-process nuclei 68Se, 72Kr, 76Sr and 80Zr exhibit large shell gap both at the proton and neutron numbers in the deformed space with the consequence that pairing correlations for protons and neutrons vanish. This lends a doubly magic character to these nuclei. A significant number of nuclei in this region are also shown to exhibit neutron magicity at N=34, 36, 38, and 40 in the deformed space. A unique case of concomitance of the double magicity and the shape-coexistence is found for 68Se.Comment: 10 pages, 4 figures; Invited contribution presented at the International Symposium on Exotic Nuclei, EXON 2009, Sochi, Russia, Sept. 28-Oct. 2, 200

The Indian Economy Since Liberalisation: the Structure and Composition of Exports and Industrial Transformation (1980 – 2000)

This paper assesses empirically structural change in the Indian manufacturing based export sector, based on an analysis of 143 industries / product groupings (mainly manufacturing industries). Trade indices such as Balassa´s revealed comparative advantage (RCA) index, and other variants commonly employed in the literature are used in our analysis. Regression analysis on the RSCA indices is used to further analyse structural change. Thereafter, the stability of the RCA indices is examined, as well as the process of their intertemporal evolution. Three technology categories (high technology, medium technology and low technology) are examined individually and SITC product codes are used as proxies for export industries, in order to look at industry movements within each of these groups. This analysis enables us to assess the export performance of Indian industries in the selected product-industry groupings in detail and evaluate the prospects for growth of particular Indian industrial groupings

Forward-backward asymmetry in top quark production from light colored scalars in SO(10) model

The forward-backward asymmetry in top pair production at Tevatron has been reconfirmed by the CDF collaboration with 5.3 fb^{-1} of accumulated data. These measurements also report that the asymmetry is the largest in regions of high invariant mass M_{t\bar{t}} and rapidity difference |\Delta Y|. We consider light colored sextet scalars appearing in a particular non-supersymmetric \10 grand unification model within the \bar{126} scalar representation. These scalar states have masses in the range of 300 \text{GeV}-2 \text{TeV} consistent with the requirements of gauge coupling unification and bounds on the proton lifetime. The cross section and the total asymmetry can be simultaneously explained with the contributions of these scalars within 1$\sigma$. We find that the simultaneous fitting of the cross section, the total asymmetry and the asymmetries in different rapidity and M_{t\bar{t}} bins gives only a marginal improvement over the SM contribution. We also study various production mechanisms of these colored sextet scalars at the LHC.Comment: 22 pages, 11 Figures, References added, Section III and V modified. Version accepted for publication in JHE

Characterizing the performance of continuous-variable Gaussian quantum gates

The required set of operations for universal continuous-variable quantum computation can be divided into two primary categories: Gaussian and non-Gaussian operations. Furthermore, any Gaussian operation can be decomposed as a sequence of phase-space displacements and symplectic transformations. Although Gaussian operations are ubiquitous in quantum optics, their experimental realizations generally are approximations of the ideal Gaussian unitaries. In this work, we study different performance criteria to analyze how well these experimental approximations simulate the ideal Gaussian unitaries. In particular, we find that none of these experimental approximations converge uniformly to the ideal Gaussian unitaries. However, convergence occurs in the strong sense, or if the discrimination strategy is energy bounded, then the convergence is uniform in the Shirokov-Winter energy-constrained diamond norm and we give explicit bounds in this latter case. We indicate how these energy-constrained bounds can be used for experimental implementations of these Gaussian unitaries in order to achieve any desired accuracy.Comment: v3: 26 pages, 10 figures, final version accepted for publication in Physical Review Researc

Free radical 5-exo-dig cyclization as the key step in the synthesis of bis-butyrolactone natural products: experimental and theoretical studies

Radical cyclization reactions were performed by 5-exo-dig mode to yield cis-fused bicyclic systems, leading to the synthesis of bis-butyrolactone class of natural products. The study was aimed at understanding the impact of alkyl side chains of furanoside ring systems in L-ara configuration on the radical cyclization. It was amply demonstrated by experimental studies that the increase in the length of the alkyl side chain has an effect on the cyclization: while efficient cyclization reactions could be realized with methyl and ethyl side chains, the yields were significantly reduced in the case of n-pentyl side chain. Theoretical studies using DFT and (RO)MP2 methods were carried out to analyze the influence of the substitution pattern on the cyclization barriers