In this talk I shall provide a brief overview of technologies where nanoscience and technology can provide value addition to both existing technologies as well as to a few emerging ones. A few specific areas of applications such as nanocomposites, nanocatalysts and energy storage shall be discussed. The second part of the talk will demonstrate how basic physics can still be a useful tool to solve a practical problem associated with quantum dot lasing. I shall discuss the physics of nanocrystal lasing and demonstrate a procedure for fabricating novel core-shell nanostructures that can eliminate the problem of non-radiative auger transition that will eventually lead to single-exciton lasing.

Nanostructures are produced on metal and semiconductor surfaces in a controllable manner via low energy ion bombardment. The resultant materials are probed with scanning probe microscopy, x-ray photoelectron spectroscopy and low energy ion scattering. A variety of nanostructures such as ripple, dot and hole are formed and controlled their shapes and sizes by tuning the ion beam parameters and ion target geometry. The self-organized nanoclusters produced by ion bombardment display quantum size effects. Neutralization of scattered alkali-metal ions is used to probe the electronic states of the nanoclusters.The work function change accompanying oxygen adsorption on metals is not always positive, as would be expected due to the surface dipole. I shall also discuss that the low energy alkali ions could be used to investigate the contribution of the dipole to the local potential near a Ta surface atom

Laser beams can be used to decelerate gas phase atoms in an ultra-high vacuum chamber. A set of six counter-propagating red-detuned circularly polarized low intensity cw laser radiations originating from a a single source and a quadrupolar magnetic field produced by coils in an anti-Helmholtz configuration can control the atomic motion in a three dimensional space. Under certain optimum conditions of laser detuning, laser intensity and the magnetic field gradient the velocity dependent optical vicous force and the position dependent harmonic force will win over the atom’s tendency to escape and lower the atomic velocity as well as push them towards the centre of the trup. We shall describe the magneto-optic trap developed in our department for confinement of Rb atoms. The trap chamber is kept at one nano-Torr pressure and Rb samples are introduced at a pressure of 10-100 Nano-Torr. The cold atom cloud has an estimated temperature of 130 micro-Kelvin and the number of confined atoms is 106 in a cloud with an approximate radius of nearly 0.1 mm.the cloud can be compressed by increasing the field current. Further work on guiding of the cold atom cloud to a second trap for achieving Bose Einstein Condensation (BEC) will be discussed.