Our research focuses on the characterization of physical properties and structures of materials through thermodynamic, transport, X-ray and neutron measurements, with an emphasis on the design, synthesis and crystal growth of new materials. Our interests span a wide spectrum of materials, from intermetallics to oxides, especially superconductors and strongly correlated electron systems showing unusual electronic and magnetic ground states that can be perturbed by chemical doping, applied pressure or magnetic field. We aim at synthesizing new materials with non-trivial properties, characterizing quantum phases, and examining the different energy scales in solids. The interplay of magnetism, superconductivity and structure will be of particular interest.
1. Fe-base high-temperature superconductors
Since 2008, the discovery of the 2nd high Tc superconducting family, Fe based superconductors (FBS) has attracted lots of research not only because high-temperature superconductivity was observed which may lead to new technology renovation, but also because in both cuprates and FBS, the only two high Tc superconductors, structural distortion, superconductivity and antiferromagnetism exist. The study of the interplay among them is important to understand the origin of unconventional superconductivity and may shed light on the discovery of room temperature superconductors. We search for new unconventional superconductors and investigate the interplay of various competing orders there.
2. Topological semimetals
The discovery of time reversal-symmetry-protected two-dimensional surface state with linear dispersion in bulk topological insulators has inspired a lot of research interests not only because of their promising applications arising from these dissipationless surface states but also because these bulk materials have broadened the horizon to search for new emergent phenomena. Recently, besides topological insulators, various topological semimetals with protected surface states have been predicted and studied, including Dirac semimetals, Weyl, nodal-line semimetals. New emergent phenomena such as Surface Fermi arc state, chiral anomaly effect, etc., have been discovered. We devote to search for new and ideal topological semimetals and investigate their novel emergent phenomena.
3. Magnetism and superconductivity in quasi-low dimensional bulk materials
Quasi low dimensional systems (dimensionality d=1 or 2) have been actively studied not only because they are more “accessible” for theoretical treatment, but also because exotic phenomena, such as spin-density waves, charge-density waves, charge order, magnetic frustration, etc., are often found in them due to strong quantum and thermal fluctuations. The competition between different order parameters makes low dimensional systems relatively easy to perturb, and rich phase diagrams can be obtained. The importance of low dimensionality is also suggested for high-temperature superconductivity since both cuprate and Fe-based high-temperature superconductors have layered structures. We study quasi-low dimensional bulk materials with the application of magnetic field, chemical doping or pressure.