Our research in experimental condensed matter physics focusses on the search for new materials where strong electronic correlations lead to novel order of moments and charges, including unconventional superconductivity and other collective states. Materials where this order is just on the verge of destabilization at a quantum critical point are of particular interest, as here the electronic structure itself is critical, passing between two very different states where the electrons are alternatively itinerant or localized.
Currently, we are working on three different projects that explore different aspects of quantum criticality:
· Designing New Higher Temperature Superconductors
· Quantum Criticality in Heavy Fermions with Geometrical Frustration
· Unconventional Superconductivity near Conventional Quantum Critical Points
We use a variety of materials synthesis techniques to develop new compounds, generally single crystals. Their essential characteristics are determined using magnetic susceptibility, specific heat, and thermal and electrical transport measurements, carried out in our own laboratory. Extreme conditions, such as ultra-low temperatures, high pressures, and high magnetic fields are all used to complement modifications to magnetic properties driven by composition. Neutron and x-ray scattering measurements are used to study their magnetic and chemical order, carried out at user facilities in the United States and in Europe.Our group is jointly based in the Department of Physics and Astronomy at Stony Brook University and the Condensed Matter Physics and Materials Science Department at Brookhaven National Laboratory. Our work is highly collaborative, and we work closely with theorists who carry out electronic structure calculations, and with other experimentalists around the world to carry out a broad range of advanced measurements.