Masses of composite fermions carrying two and four flux quanta: Differences and similarities

This study provides a theoretical rationalization for the intriguing experimental observation regarding the equality of the normalized masses of composite fermions carrying two and four flux quanta, and also demonstrates that the mass of the latter type of composite fermion has a substantial filling factor dependence in the filling factor range $4/17 > \nu > 1/5$, in agreement with experiment, originating from the relatively strong inter-composite fermion interactions here.Comment: 5 pages, 2 figure

Full quantum solutions to the resonant four-wave mixing of two single-photon wave packets

We analyze both analytically and numerically the resonant four-wave mixing of two co-propagating single-photon wave packets. We present analytic expressions for the two-photon wave function and show that soliton-type quantum solutions exist which display a shape-preserving oscillatory exchange of excitations between the modes. Potential applications including quantum information processing are discussed.Comment: 7 pages, 3 figure

Counter-intuitive influence of Himalayan river morphodynamics on Indus Civilisation urban settlements

Urbanism in the Bronze-age Indus Civilisation (~4.6–3.9 thousand years before the present, ka) has been linked to water resources provided by large Himalayan river systems, although the largest concentrations of urban-scale Indus settlements are located far from extant Himalayan rivers. Here we analyse the sedimentary architecture, chronology and provenance of a major palaeochannel associated with many of these settlements. We show that the palaeochannel is a former course of the Sutlej River, the third largest of the present-day Himalayan rivers. Using optically stimulated luminescence dating of sand grains, we demonstrate that flow of the Sutlej in this course terminated considerably earlier than Indus occupation, with diversion to its present course complete shortly after ~8 ka. Indus urban settlements thus developed along an abandoned river valley rather than an active Himalayan river. Confinement of the Sutlej to its present incised course after ~8 ka likely reduced its propensity to re-route frequently thus enabling long-term stability for Indus settlements sited along the relict palaeochannel

A Validated Densitometric Method for Analysis of Atorvastatin Calcium and Metoprolol Tartarate as Bulk Drugs and In Combined Capsule Dosage Forms

A simple, accurate and precise high-performance thin-layer chromatographic method has been developed for the estimation of Atorvastatin Calcium and Metoprolol Tartarate simultaneously from a capsule dosage form. The method employed Silica gel 60F 254sprecoated plates as stationary phase and a mixture of Chloroform: Methanol: Glacial acetic acid (dil.) :: (9:1.5:0.2 ml %v/v) as mobile phase. Densitometric scanning was performed at 220 nm using Camag TLC scanner 3. The method was linear in the drug concentrations’ range of 500 to 2500 ng/spot for Atorvastatin Calcium, also for Metoprolol Tartarate with correlation coefficient of 0.984 for Atorvastatin Calcium and 0.995 for Metoprolol Tartarate respectively. The retention factor for Atorvastatin Calcium was 0.45 ± 0.04 and for Metoprolol Tartarate was 0.25 ± 0.02. The method was validated as per ICH (International Conference on Harmonisation) Guidelines, proving its utility in estimation of Atorvastatin Calcium and Metoprolol Tartarate in combined dosage form

Hamiltonian Theory of the FQHE: Conserving Approximation for Incompressible Fractions

A microscopic Hamiltonian theory of the FQHE developed by Shankar and the present author based on the fermionic Chern-Simons approach has recently been quite successful in calculating gaps and finite tempertature properties in Fractional Quantum Hall states. Initially proposed as a small-$q$ theory, it was subsequently extended by Shankar to form an algebraically consistent theory for all $q$ in the lowest Landau level. Such a theory is amenable to a conserving approximation in which the constraints have vanishing correlators and decouple from physical response functions. Properties of the incompressible fractions are explored in this conserving approximation, including the magnetoexciton dispersions and the evolution of the small-$q$ structure factor as \nu\to\half. Finally, a formalism capable of dealing with a nonuniform ground state charge density is developed and used to show how the correct fractional value of the quasiparticle charge emerges from the theory.Comment: 15 pages, 2 eps figure