Condensed Matter and Materials

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Condensed Matter Physics at Carolina comprises theoretical and experimental research projects of 13 faculty, about 30 graduate students, and several visitors and adjunct faculty. The topics of research are broadly distributed from ab initio calculations of material structure in fullerenes to Zeeman splitting measurements in one-dimensional conductors. Collaborations outside of the department are emphasized to the benefit of students who are exposed to a greater variety of science and applications of their science. Industrial sites (such as DuPont, IBM, Kobe, Lucent Technologies and the Research Triangle Institute), national laboratories (e.g. NIST, NREL, Argonne, ORNL), other academic institutions (such as Duke, NC State, and The University of Illinois) and other departments (especially Chemistry and Computer Science) within UNC-CH have ongoing joint research projects with the condensed matter faculty.

Among the studies currently underway is a large interdisciplinary (materials science, chemistry, physics and computer science) research project on the science of carbon nanotubes (fullerene tubes), which seeks to understand and to control their fundamental properties for use in future technologies. This effort is closely coupled with a microscopy research effort that collaborates with Computer Science to develop new imaging techniques and advanced user interfaces to perform nanometer-scale investigations of nanotubes, DNA and viruses. The systems under study at present include the mechanical, friction and electrical properties of carbon nanotubes and devices made from them. Biophysics studies, in collaboration with Chemistry and Health Sciences, include the infectious pathways of viruses and the mechanical properties of DNA, viruses and fibrin. (See also our biophysics pages.) Other faculty are engaged in plasma-based synthesis and characterization of thin film materials for acoustic, bioactive, and electronic applications. This research centers on nucleation, interface modification, and characterization of novel materials ranging from carbon nanostructures for field emission to bonelike ceramics for improved bioreactivity and osseointegration. Nuclear magnetic resonance is used in the study of structure, dynamics, and electronic properties of bulk metallic glasses and supercooled liquids, quasicrystals, amorphous semiconductors, and carbon nanotubes.

Additional experimental research programs involve combinatorial MBE synthesis and characterization of novel metallic thin films and heterostructures and carbon nanotubes, effects of surfaces and interfaces, magnetic and transport effects in doped perovskite epitaxial films and in transition metal epitaxial films and superlattices; as well as optical studies of carbon nanotubes, organic semiconductors, and magnetic semiconductors using Raman, Brillouin, photoluminescence, optical absorption, and FTIR spectroscopies. Experiments on quantum transport study the behavior of electrical devices in situations where quantum effects dominate. Two examples are ballistic motion that can lead to exotic effects like chaos and quantum interference. Theoretical studies include a unified self-consistent treatment of the structural, thermodynamic, and electronic properties of the alkali fluids.

Theoretical research on fullerene structure and properties, high-Tc superconductor properties, metal nitride structure and properties, liquid-vapor transitions in metals (where there is an accompanying metal-insulator transition), optical properties of semiconductors and insulators, and polymer (liquid crystal) order are actively pursued here. The experimental research covers three principal areas in fundamental physics: optical spectroscopy (Brillouin, Raman, photo- and electro- luminescence non-linear response, continuous wave and pulsed, IR through UV), magnetic resonance spectroscopy (on a vast array of materials from wax to quasicrystals) and transport studies (mostly in the quantum regime); studies of amorphous and microcrystalline silicon; and two materials science efforts: plasma growth, etching and control of semiconductors and ion-beam analysis and alteration of a variety of materials.

Facilities on site include state-of-the-art femtosecond non-linear pulsed optical spectrometers and NMR spectrometers, a 2.5MV Van de Graaff accelerator used for ion beam analysis (Rutherford backscattering/channeling), a 200 keV ion implanter, and a Quantum Design SQUID magnetometer. Specialized apparatuses include a Raman and photoluminescence spectrometers, and diamond-anvil cells for optical studies at pressure up to megabars, ECR and ICP research plasma systems, a Digital Instruments Nanoscope III scanning probe (STM and AFM), which has been connected to a virtual reality control unit, a dilution refrigerator and magnet for quantum transport experiments done to 0.01K at fields up to 16 Tesla, and an advanced molecular beam epitaxy growth and analysis system. Ancillary equipment such as test stations, chemical hoods, furnaces and so on are available as well.