Search NASA⌕ Search

Engineering topics

Zainuddin, H.

Publications and source records attributed to Zainuddin, H..

First-principle study of geometric stabilities, electronic and magnetic properties of low coverage vanadium adsorption on graphene

Stable geometries, electronic and magnetic properties of low coverage vanadium (V) atoms adsorption on graphene sheet have been investigated by first principles calculations, using generalized gradient approximation. Calculation shows that center of the ring is energetically favorable for both V adatom and perpendicular dimer after relaxation. Moreover, the proportion of orbital contribution of C-V bonding are mainly dominated by 2p{sub z} orbital of C and partially occupied by the 3d like states of V. It is also found that the low coverage V atom adsorbed graphene system is metallic and magnetic, and has demonstrated additional hint on its usefulness in magnetic devices.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Numerical method for computing Maass cusp forms on triply punctured two-sphere

A quantum mechanical system on a punctured surface modeled on hyperbolic space has always been an important subject of research in mathematics and physics. This corresponding quantum system is governed by the Schrödinger equation whose solutions are the Maass waveforms. Spectral studies on these Maass waveforms are known to contain both continuous and discrete eigenvalues. The discrete eigenfunctions are usually called the Maass Cusp Forms (MCF) where their discrete eigenvalues are not known analytically. We introduce a numerical method based on Hejhal and Then algorithm using GridMathematica for computing MCF on a punctured surface with three cusps namely the triply punctured two-sphere. We also report on a pullback algorithm for the punctured surface and a point locater algorithm to facilitate the complete pullback which are essential parts of the main algorithm.

97 MATHEMATICS AND COMPUTING↗