The study of quantum magnetism, a major focus of Professor Daniel Reich's research, focuses on the strange and beautiful properties of spin chains and ladders. In these systems the magnetic couplings are effectively one dimensional, and the quantum mechanics of spin in low dimension leads to a panoply of exotic effects, including spin gaps, field-induced phase transitions, soliton excitations and "Luttinger liquid" behavior. These phenomena are studied by neutron scattering and low temperature thermodynamic measurements.     The general theme for Professor Collin Broholm's research is the examination of many-body systems in the vicinity of zero-temperature quantum phase transitions. More often than not, phase transitions take place at finite temperatures as the thermal energy becomes less than a characteristic energy scale of the system. It then becomes favorable to change the symmetry and nature of the material (e.g. from a liquid to a solid as water freezes). However, several examples of quantum phase transitions between disordered and ordered phases that occur at T=0 have recently emerged, and deserve attention because of the rich and unexplored properties of quantum disordered phases. Collin Broholm carries out neutron scattering experiments at the Cold Neutron Research Facility at NIST in Gaithersburg, Md, near Washington D.C.

    For many condensed matter systems a failure to achieve equilibrium can dominate the behavior, and understanding the resulting non-equilibrium states becomes crucial to their accurate description. Professor Robert Leheny's research explores the structure and dynamics of disordered and out-of-equilibrium systems, with a particular focus on model complex fluids and glass-forming materials. The primary techniques he uses are x-ray and neutron scattering, and dielectric susceptibility. Topics on which his group is currently focusing include: aging in molecular glass forming liquids, the behavior of liquid crystals confined in compliant gels, and (in collaboration with Prof. James Harden's group in Chemical Engineering) the structure and rheology of synthetic clay suspensions.

    Facilities include dilution-refrigerator-based low-temperature equipment and systems for molecular beam epitaxy, ultra high vacuum thin film deposition, pulsed-laser deposition, Mossbauer spectroscopy, and optical and electron-beam lithography. Among other instruments available are a four- circle X-ray diffractometer, scanning electron microscope, LEED-Auger surface analyzer, and a SQUID magnetometer. Additional sample preparation, characterization, and measurement systems are available through the MRSEC.

Theorists:
    Professor Tesanovic studies fluctuations and correlations in high temperature and related superconductors and physical phenomena at high magnetic fields, with emphasis on superconductivity and the quantum Hall effect.
   Professor Robbins studies a variety of non-equilibrium systems, using both analytical methods and high performance computing. He has in recent work examined the molecular underpinnings of friction, adhesion and spreading, and studied the effect of disorder on interface dynamics in magnets and fluid systems.
    Professor Emeritus Judd has recently been applying group theory to the study of crystals. Of particular interest is the Jahn-Teller effect, the spontaneous distortion of symmetric crystals when the energy levels of the active ions exhibit a degeneracy. Particular attention is being paid to Jahn-Teller systems of octahedral symmetry, in which all kinds of higher symmetries are sometimes exhibited under special conditions of the couplings and vibrational frequencies of the lattice.