Experimental Condensed Matter Group

UNH has an emerging program in condensed matter physics that involves three exciting areas of research. The first is the study of Atomic Clusters, tiny aggregates comprising from just two or three to thousands of atoms. These largely unexplored systems offer a remarkable example of interdisciplinary interest, since they are relevant to topics as diverse as molecular physics, catalysis, astrophysical chemistry, crystal growth, solid state physics, and materials science. Fullerenes, also called "buckyballs", are the best known representative of atomic clusters. These hollow, all-carbon clusters are chemically stable under ambient conditions, but they feature several competing reaction channels when highly excited by a laser pulse. Moreover, it is possible to implant atoms into the fullerene cage (Professor Olof Echt).

The second area of research in condensed matter physics is experimental Surface Science. The field is driven by the quest for smaller, faster, brighter and longer-lived in the development of electronic, magnetic, and photonic devices resulting in ever greater miniaturization and growing importance of surfaces, interfaces, and thin films as surface-to-volume ratios increase. The physical properties of low-dimensional structures are in general very different from those of bulk matter. If at least one dimension of such structures is small enough that quantum-mechanical effects become important, their electronic, magnetic, and catalytic behavior is particularly fascinating. Our research involves the study of the interplay of electronic, vibrational and structural surface properties at the atomic scale. Specific measurement techniques in ultra-high vacuum include atomic resolution scanning tunneling microscopy (STM) and photoelectron spectroscopy utilizing synchrotron radiation sources. Currently two advanced Ph.D. students in our group are investigating different aspects of the dynamics of self-assembly of nanoscale structures at strained metallic surfaces by STM (Professor Karsten Pohl).

The third area of research in condensed matter physics is the science of Thin Films. We use evaporation, pulsed laser deposition and ion beam assisted sputter deposition to control the growth environment in novel ways. One example is to provide low energy ion bombardment at a non-normal angle of incidence during deposition to induce in-plane alignment of the microstructure of thin films. Such highly oriented polycrystalline thin films can be used as templates for subsequent growth of new materials. We are particularly interested in combining different kinds of materials on short length scales to create nanocomposites with unusual properties (Professor James Harper).

Professors: Olof Echt, Jim Harper (affiliate), Karsten Pohl