Faculty Research
Mark Bowick
is a theoretical and computational physicist
whose work focuses on the relation between geometry
and order in a wide variety of soft condensed matter systems.
He has carried out computational and analytical studies of the properties of
membranes and random surfaces; this work revealed a tubular phase
transition in anisotropic membranes.
His work also includes
both experimental and theoretical studies of topological defect formation
during the isotropic to nematic phase transition in liquid crystals;
these string defects are a laboratory analog for cosmic string
formation during the cooling of the early universe.
Most recently, much of Prof. Bowick's research has been directed at understanding
"spherical crystals", with applications to colloidosomes and viruses.
Professor Bowick is
is principle investigator on a
National Science Foundation Information Technology and Research grant
"Statistical Physics and Computational Complexity", through the
Division of Materials Research. Visit Bowick's
Home Page.
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Kenneth Foster and Jureepan Saranak's
overall research goals are to understand how biological sensors -- in
particular light sensors --work, and how they have evolved over the
last few billion years on Earth. We are studying model cell systems
from three major biological Kingdoms: the Green Alga, Chlamydomonas
reinhardtii the Fungal zoospores of Allomyces reticulatus, and the
Stramenopiles, Mallomonas and Fucus sperm. Various aspects are under
investigation at different biological levels. For example, for
unicellular vision we are studying the architecture of its light
capturing structure, a dielectric antenna or eye. At the cellular
level, the nonlinear ciliary responses that enable the cell to use its
eye to track the direction of light are being analyzed. At the
intermolecular level, we are employing systems analysis to describe the
network of sensory signals within a single cell. Some of these signals
come from light receptors at the eye and are used to steer the cell
with its cilia. At the molecular level, we are studying how the light
receptor molecules work. Specifically, we seek the mechanism of
activation of the rhodopsin and other G-protein-activating receptors is
being sought. With the conservation of nature, hundreds of different
receptors in human would appear to be in the same superfamily, first
evolved 3.5 billion years ago. Techniques developed for this work are
also being applied, in collaboration with others, to understand the
ubiquitous pathways by which light can control of gene expression.
Professor Foster is principal investigator (with professors Lipson and
Saranak) of the grant "Nonlinear Dynamics of Cellular Signal
Transduction" from the National Institutes of Health. Visit Ken and
Juree's Home Page.
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Arnold Honig
is an emeritus professor whose laboratory has worked primarily in two fields: experimental
semiconductor physics (with an emphasis on the persistent
photoconductivity effect found in GaAs, CdS, and other semiconductors),
and the production and characterization of nuclear spin polarized
hydrogen-deuteride (HD). This unique material is prepared at Syracuse
under extreme conditions of high magnetic fields and low temperatures.
The spin physics involved in its production is fascinating, and the
spin-polarized material is used for experiments in nuclear physics and
fusion. Spin-polarized HD based on the Syracuse work is of crucial
importance as the target for upcoming experiments at Brookhaven
National Laboratory. In recent years Honig has also been working on
methods for preparing "hyperpolarized" nuclei for use in magnetic
resonance imaging. There is substantial current activity using
optical-pumping methods to produce hyperpolarized 129Xe and 3He; the
cryogenic methods developed in Honig's laboratory present an
alternative to the optical-pumping approach. Prof. Honig is a recipient
of the Syracuse University Chancellor's Citation for Exceptional
Academic Achievement. Visit Honig's Home Page.
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Edward Lipson’s
research spans three areas (one basic and two applied): a) photosensory
transduction in model microrganisms, b) human-computer interface (HCI)
technologies and distributed medical intelligence (DMI; related to
“telemedicine”), and c) medical imaging. Lipson’s basic research on
sensory transduction began with studies of an organism called
Phycomyces, but in recent years has shifted to the Chlamydomonas
project led by Kenneth Foster. Professor Lipson is co-principal
investigator on the grant "Nonlinear Dynamics of Cellular Signal
Transduction" from the National Institutes of Health, of which Prof.
Foster is the principal investigator. The HCI/DMI work, described at
http://www.pulsar.org (jointly led by David Warner MD, PhD and by
Lipson), includes development of core technology (electronic devices,
sensors, transducers, and software) for applications in disabilities,
healthcare, national security, etc. (supported by a grant from the
defense department). The main effort to date on the medical imaging
project, led by Prof. Andrzej Krol of Upstate Medical University
(Radiology) involves noninvasive nuclear medicine and magnetic
resonance imaging approaches for diagnosis of breast cancer as
noninvasive alternatives to surgical biopsy following suspect
mammograms. A related project involves nuclear cardiology. Prof. Lipson
is an adjunct professor of Radiology at Upstate and Prof. Krol is
adjunct in our department. See
http://www.ecs.syr.edu/research/imaging/.
Visit Lipson's Home Page.
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Cristina Marchetti
has recently been doing theoretical research on high-temperature
superconductors, and in particular upon the magnetic flux lines which
thread these new materials when even a modest magnetic field is
applied. These flux line arrays are crucial to the properties of the
superconductor, since their motions lead to dissipation and the decay
of superconductivity. In addition to the flux line work, Marchetti has
published recently on: Dynamical properties of dense classical liquids.
High field transport and carrier relaxation in semiconductor
heterostructures. Collective transport in driven, disordered systems.
Flux line arrays are one example; another is charge density waves in
anisotropic materials. Professor Marchetti is principal investigator of
the theoretical condensed matter physics grant "Nonequilibrium Dynamics
of Disordered Condensed Matter Systems" from the National Science
Foundation and co-principal investigator on a National Science
Foundation Information and Technology Research grant "Statistical
Physics and Computational Complexity"; she is also a Fellow of the
American Physical Society. Visit Marchetti's Home Page.
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Alan Middleton does theoretical research in the areas of condensed matter and
statistical physics. Topics which he has published work on include: The
dynamics of magnetic flux lines in superconductors The current-voltage
characteristics in arrays of "quantum dots" (lithographically created
electronic devices) Materials with sliding charge-density waves. These
physical systems are related in that they are examples of dynamical
systems with many degrees of freedom; such systems can exhibit complex
behavior and novel phase transitions. A major focus of Middleton's work
is the use of computers to understand these complicated systems. In
particular, he has worked on developing algorithms and computational
approaches which obtain the answers for large systems quickly. He
therefore works with computer scientists on some of these problems and
applies techniques developed in computer science. Professor Middleton
is principal investigator of the theoretical condensed matter physics
grant "Phases and Dynamics of Disordered Condensed Matter Systems" from
the National Science Foundation and a co-principal investigator on a
National Science Foundation Information and Technology Research grant
"Statistical Physics and Computational Complexity". Visit Middleton's Home Page.
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Liviu Movileanu's laboratory
uses a multidisciplinary approach to study problems in the range from fundamental science to bionanotech applications. His work is at the cutting edge of membrane (1), ion channel (2), polymer (3) and single molecule (4) biophysics. Replacing the components (1-4) makes simple systems highly relevant for a variety of situations from biology and biotechnology. Much of his work involves the study of nanopores: molecule sized openings. The transport of peptides, proteins, and DNA through these channels is relevant to both physics and biology. Other molecular biology and protein chemistry techniques are used, when necessary.
Visit Movileanu's Home Page.
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Britton Plourde
studies quantum coherence and vortex dynamics in microfabricated superconducting devices. These devices have features as small as 100 nm, and the measurements take place at temperatures near absolute zero. Quantum coherent superconducting devices are one of the leading candidates for the building blocks, or "qubits", of a quantum computer. Such a computer would be capable of solving many problems which are intractable on even the most powerful classical computer. Plourde's research focuses on fabricating these superconducting qubits, optimizing the techniques for reading out their quantum state, minimizing the decoherence of the qubits, and developing techniques for entangling qubits together. Vortices in superconductors exhibit a rich variety of phenomena as they interact with currents, defects, and each other. By patterning particular defect structures, it is possible to control the location and motion of these vortices. Plourde's group explores such microfabricated pinning potentials to investigate quantum coherent vortex behavior, as well vortex ratchets, which can produce directed transport of vortices in response to an oscillatory driving force.
Visit Plourde's Home Page.
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Eric Schiff's
research primarily involves experimental study of unconventional
semiconductors. Mostly the material of interest has been hydrogenated
amorphous silicon (usually denoted a-Si:H). This material started out
as a physicist's plaything. a-Si:H was the first non-crystalline
semiconductor which had electrical properties even remotely similar to
crystalline semiconductors such as silicon or gallium arsenide, and its
structural, electrical, and optical properties are extremely
interesting. Somehow a-Si:H has now gained enormous commercial
significance: it is the basis of "active matrix" flat panel displays
used for notebook computers, and is also widely applied in inexpensive
solar cells for consumer applications and power generation. Recently,
Schiff has gotten interested in porous electronic materials. Porous
silicon has the property that it emits light fairly efficiently at room
temperature (single crystal silicon doesn't). Porous titania is the
basis of a novel solar cell invented by O'Regan and Graetzel. Both
materials behave differently than either homogeneous amorphous or
homogeneous crystalline materials. Schiff's research group has
particular expertise in fundamental measurements of electron and hole
mobilities, electron spin resonance measurements on defects, and
electroabsorption measurements addressing the device physics of solar
cells. Professor Schiff is principal investigator of the research
contract "Electroabsorption and Transport Measurements and Modeling
Research in Amorphous Silicon Based Solar Cells" from the National
Renewable Energy Laboratory. Visit Schiff's Home Page.
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Jen Schwarz
is a theoretical physicist who is interested in
such questions as (1) How do
systems jam? (In other words, how do those darn coffee beans
get stuck in their hopper?), (2) How does a cell crawl and/or change
its shape to heal a wound or inflict damage if it's a cancerous beast?
and (3) How does "order", a.k.a. life, emerge from randomly interacting
units---a question IDers refuse to even ask?
Visit Schwarz's Home Page.
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Gianfranco Vidali's
research is centered on the study of physical and chemical processes
occuring at surfaces under well characterized conditions. Currently,
his group is working in two areas: (1)
Preparation and
characterization of thin solid films in far-from-equilibrium
conditions. The structure, overall morphology, and dynamics of films,
from submonolayer to hundreds of layers, are studied in-situ and in
real time (while growth proceeds) using He beam scattering and
LEED/Auger surface probes. (2) Most recently, his group has studied the
growth of films on substrates where there is both a large lattice
mismatch and also large supersaturation, which is of considerable
interest for the preparation of next-generation thin film devices.
Gas-surface interactions occurring in interstellar space. Vidali's
group is investigating how molecular hydrogen, and more complex
molecules, are formed in the interstellar space. In the laboratory, his
group studies hydrogen recombination and hydrogenation reactions on
surfaces at low temperature and under conditions mimicking the actual
interstellar space environment. Vidali's laboratory houses an atomic
beam scattering apparatus which was designed and built in-house. It
incorporates both helium and atomic hydrogen beam lines, one ultra-high
vacuum scattering chamber, a preparation chamber, and two beam
detectors. Vidali has also worked on theoretical problems related to
the physical adsorption of quantum gases on surfaces at low temperature
and on computer simulations of thin film growth. Professor Vidali is
principal investigator of the laboratory astrophysics grant "Energetics
of Molecular Hydrogen Formation on Surfaces of Astrophysical Interest"
from the National Aeronautics and Space Administration. Visit Vidali's Home Page.
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Marcel Wellner is an emeritus professor who does biological physics research in collaboration with scientists at neighboring Upstate
Medical University. The research involves the propagation of electric
waves in the living heart muscle. Such waves ordinarily occur in the
healthy heart, where they are needed to trigger the heartbeat.
Occasionally, however, waves will propagate anomalously, thereby
causing dangerous or lethal "arrhythmias." The Upstate group studies
these phenomena using observational, experimental, computational, and
theoretical approaches. Wellner has fruitfully applied his extensive
research experience in field theory to these effects. Visit Wellner's Home Page.
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Xiangjun (Sean) Xing's
research interests include elasticity theory, hysteresis, plasticity theory, and glassy physics. He has a long standing interest in the elasticity of various kind of soft materials such as liquid crystals (LC), membranes, and liquid crystalline elastomers (LCE). The common features of these systems are: importance of thermal fluctuations, partial breaking of space symmetries, quenched disorders and ability of large deformations. Study of their elasticity necessitates essential modification of the classical elasticity theory. His ongoing research also concerns a phenomenological approach to zero temperature, rate independent hysteresis and plasticity. One central issue is return point memory (or work hardening) and its possible violation. He is studying existing phenomenological theories, such as Preisach models, Stoner-Wohlfarth model, and various plasticity models and their possible extensions. The object is to understand mechanisms of memory (how system remember its history) in various kinds of zero temperature non-equilibrium systems, and how interactions and frustrations affect these mechanisms. Another interesting problem is to derive these phenomenological theories from more fundamental descriptions such as random field Ising model (RFIM) or the Sherrington-Kirkpatrick (SK) model. When thermal fluctuations are appropriately included, these phenomenological models can also be used to study aging dynamics in glassy systems.
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