Annual Report 2006-2007

Physical Sciences

The research projects and programmes supported under Physical Sciences covered a wide range of emerging topics. The technical evaluation was done by Programme Advisory Committees (PACs) on (a) Condensed Matter Physics and Materials Science, (b) Plasma Physics, High Energy Physics, Nuclear Physics, Astronomy & Astrophysics, Nonlinear Dynamics and (c) Lasers, Optics and Atomic and Molecular Physics. The PACs also monitored the progress made in ongoing projects on a regular basis.

Condensed Matter Physics and Materials Science:

A large number of projects were sanctioned on some of the following subjects of study during the year preparation and study of hydrogenated microcrystalline silicon thin films by Hotwire Chemical Vapor Deposition method for solar cell applications; ion transport in proton conducting polymer gel electrolytes and nanogels; p-type transparent conducting CuAIO2 thin films for transparent electronics; magneto-transport in giant magnetoresistive multilayers; dynamic studies in the phase transition region of Sm C*-Sm A phase in electroclinic liquid crystal materials; structure and dynamics of biomolecular complexes and their application in drug delivery; dielectric properties of polyamide-phenol compounds for use as thermo-sensitive and humidity sensitive device; spectroscopic investigation of semiconductor nanostructure fabricated by laser-induced electrochemical etching; conformation and phase transformations of charged and uncharged polymers confined at interfaces; synthesis and characterization of solid polymer electrolytes containing nanoscale fillers for ionic devices; high pressure Mossbauer and electrical resistivity studies on ion-based compounds; magnetoelectric effect in piezomagnentic- piezoelectric composites; and, transport mechanism in silver oxysalt based amorphous super ionic conductors.

Apart from the above, two scientists were awarded Ramanna Fellowships based on the excellent work done in their earlier SERC projects.

Several interesting results were reported from ongoing projects. In one of the projects, sol-gel synthesis of various ferrite nano particles such as Mn.5Zn.5Fe2O4 and NiFe2O4 and their detailed characterization were carried out. It was shown that ferrite particles of different sizes and good nanodispersity could be synthesized routinely. An experimental set-up to measure ac susceptibility was also developed in this project. In another project, the FP-LMTO method was used to study small size copper clusters (13 atoms) and larger clusters (55 atoms) were studied using the ETB method. Calculations on Mn, MnAs and Co clusters were carried out by the VASP code employing PAW potentials. The self-consistent ASR method had been used to study planar and rough surfaces of Fe, Ni, and planar surfaces of Co and FeV alloys.

Plasma, High Energy, Nuclear Physics, Astronomy & Astrophysics and Nonlinear Dynamics:

Following were the subjects of study of the projects sanctioned this year- study of certain nonlinear phenomena with different external forces and noises; formation of super heavy nuclei and their survival probability; study of CP-violation with Belle detector at KEK B Factory; phenomenology of B Decays in and beyond the Standard Model; unified investigation of Fusion, Resonance and Scattering in Heavy Ion Collisions; Minimal Supersymmetric Grand Unified Theories; laser plasma interactions, specially on parametric instabilities and wakefield; and, basic experiments on multicomponent plasma with negative ions.

In addition to the above projects, five scientists were awarded Ramanna Fellowships.

Several interesting results emanated from ongoing projects. For example, in a project at IIT Kharagpur, the study of redshift space distortions in galaxy distribution using N-body simulations as well as observed data, had been done. Computational tools to perform N-body simulations, and to quantify filamentarity in galaxy distribution, had been developed. The latter, on application to data from large redshift surveys, had revealed new and interesting features including a luminosity dependence on the bias parameter. In another project at the University of Bombay, Mumbai, studies on production mechanism in nuclear collisions, - nucleus potential near threshold and cross section estimates for -mesic nuclei formation had been carried out. Among the highlights were (i) a two-step model with proper final state interaction of with nuclei for nuclei up to 4He; and (ii) exploration of -nucleus quasi-bound, bound and resonance states using time delay method. The results showed that (i) two-step production mechanism seemed inadequate to account for the data at energies away from threshold; (ii) the physics at short distances in nuclei seemed to be governed by mesons and nucleonic resonances rather than quarks and gluons; and (iii) there was a strong possibility that -mesic nuclei existed.

Lasers, Optics, Atomic and Molecular Physics:

Following were the scientific topics on which research projects were sanctioned during the year-design and development of the next generation index guided photonic crystal fibre; steady-state and time-resolved fluorescence microscopy to resolve high Q modes; effects of high Q-MDR in organic dyes, effect of these high-Q-MDR on modification of radiative rate and lasing properties of the dyes in microparticles; theoretical calculations on the MDR; optical properties of appropriately synthesized and characterized self-assembled semiconductor quantum dots of Si, Ge and GaAS and their correlation with the electronic structure using mainly photoluminescence and Raman spectroscopy; applications of group theoretical methods to quantum optics; effect of confinement on the spectroscopic properties of atomic systems; theoretical justification of some of the experimentally observed aspects such as changes in ionization potential, excited states and spectral lines; preparation, characterization and investigation of the use of CdS, CdSe and CdTe nano particles embedded polymer matrices for optical limiting applications based on optical nonlinearity; studies on optical vortices by using diffractive optical elements; and, design of optimum filters for correlation based pattern recognition.

Several interesting results were reported from ongoing projects. In a project using commercially available mono-dispersed colloidal suspensions of organic materials, very high optical quality samples were synthesized and characterized. Standard opal samples made with SiO2, polystyrene and PMMA were studied in the UVvisible range. Theoretical studies of the side polished fibre (SPF) interacting with the multimode overlay waveguide (MMOW) were carried out for gain flattening of EDFA in another project. Multimode planner waveguides for polymer were also fabricated using spin coating method and characterized using prism coupling technique in order to realize an all solid-state and rugged device. In another project, a numerical code for atom-atom scattering using close coupling approximation (CCA) model at thermal energies was developed. Hydrogen-hydrogen (H-H) scattering system at thermal energies was also investigated using the same model.