RESEARCH SYNOPSIS:

I have been heavily involved in many emerging areas of atomic, molecular, solid state, and chemical physics, throughout the historical period of rapid evolution in surface physics.

Emphasis has been placed on insightful theoretical modeling of fundamental processes involved in spectroscopic measurement techniques, in the dynamic response of complex, many-body systems to external perturbations, and in atomic and molecular reaction dynamics, particularly at surfaces. My longterm activities in a given field have been presented in original research papers, culminating in one or two major review articles or book chapters on the topics, as listed below. At all times, special effort has been invested in demonstrating the commonality and unity of physical phenomena, from one specialized area to another.

1. Chemisorption Theory:
   1. Interaction of Atoms and Molecules with Surfaces, in "Phys. of Materials", Vol.II, ed.by J.M.Blakeley, Academic, NY (1975).
   2. Adsorption on Metal Surfaces: Some Key Issues, in NATO ASI, "Atomistics of Fracture", ed. by R.M.Latanision and J.Pickens, Plenum, NY (1983).
2. Field Emission Spectroscopy:
   1. Field Emission Energy Distributions (FEED), (with E.W.Plummer), Rev. Mod. Phys. 45,487(1973).
   2. Vacuum-Tunneling Spectroscopy, (with E.W.Plummer and D.R.Penn), Phys.Today 28,(1975).
3. Angle Resolved Photoemission Spectroscopy:
   1. Electron Spectroscopy of Surfaces via Field and Photoemission, in NATO ASI, "Electronic Structure and Reactivity of Metal Surfaces", ed. by E.G. Derouane and A.A.Lucas, Plenum, NY (1976).
   2. Electron Spectroscopy and Chemical Bonding, (with T.N. Rhodin), in "The Nature of the Surface Chemical Bond", ed.by G.Ertl and T.N. Rhodin, North Holland, Amsterdam (1979).
4. Core Level Spectroscopy:
   1. Many Body Effects in Photoemission, in "Photoemission and the Electronic Properties of Surfaces", ed. by B.Feuerbacher, B.Fitton, and R.W.Willis, Wiley, Chichester (1978).
   2. Core level Spectroscopy: A Dynamics Perspective, Phys.Scripta 35,171 (1987).
5. Vibrational Spectroscopy:
   1. On Vibrational Lineshapes of Adsorbed Molecules, (with A.C. Luntz), Surf.Sci. 144,429 (1984).
   2. Excitation Mechanisms in Vibrational Spectroscopy of Molecules on Surfaces, in "Vibrational Spectroscopy of Molecules on Surfaces", ed. by J.T. Yates and T.E. Madey, Plenum, NY (1987).
6. Dynamics:
   1. Surface Harpooning, Comments Atomic Mol. Phys. 16, 219 (1985).
   2. Vibrational excitation in molecule-surface collisions. Analytical modeling vs. classical trajectories, J.Chem.Phys. 86,5196(1987).
   3. The Semiclassical Way to Molecular Dynamics at Surfaces, Ann. Rev. Phys. Chem. 39,395 (1988).
7. Chaos in Surface Processes:
   1. Chaos in Surface Dynamics, in "Chemistry and Physics of Solid Surfaces VIII", ed. by R.Vanselow and R.Howe, Springer-Verlag, Berlin(1990).
   2. Energy Dependence of Collision Characteristics in Molecule-Surface Collisions (with V.Balasubramanian, A.Bahel, I.P.Dubey, and N.Sathyamurthy), J.Phys.Chem. 96,7870(1992).
8. Femtochemistry at surfaces

   1. A similar philosophical approach has been adopted for my current and future research, one component of which is focused on the developing scientific and technological areas which require an ability to understand, "monitor", and control molecular and condensed matter processes on an atomic geometrical scale and on a sub pico-second time scale. In order to provide at a minimum, the knowledge to contemplate and rationalize the atomic behavior responsible for these processes and better still, the insight to guide and predict classes of behavior and to suggest definitive experiments proving (or disproving) the new conjectures, such theoretical inquiry is essential. Femtochemistry at surfaces is a very promising, fundamentally new approach under study.

9. Chemistry in tunnel structures

   1. Novel applications of solid state tunnel structures and the scanning tunneling microscope both as hot electron sources for induced surface processing and also as interesting entities on their own, are under study.