Our group is focused on the discovery and synthesis of new materials in single crystal form with unusual magnetic and electronic ground states as well as coupling between them. We are particularly interested in, however not limited to, magnetism, superconductivity, and quantum criticality. The “Exploratory Synthesis of Quantum Materials” research program at Simon Fraser University tightly couples materials synthesis and characterization with a strong interdisciplinary research element spanning physics, chemistry and materials science. Finding better or novel functional materials is critical for nearly every aspect of our society, including those related to the energy challenge and environmental management. Thus, highly dedicated work will be required to synthesize these materials, where structural disorder must be minimized, the properties are interesting, but materials are easy to prepare.
Spin liquid state and frustrated magnetism in metals
Until now, the study of frustration has concentrated on magnetic properties of Mott insulating oxides, where electrons are localized due to strong Coulomb interactions, and demonstrated that the frustration can lead to very unusual states of matter, including spin-supersolids, spin-ice, and spin-liquid states. The realization of the quantum spin liquid, an entangled magnetic quantum state with topological ordering and fractionalized spin excitations, has been a long-standing challenge in condensed matter physics. For the insulators, it is natural to approach the problem of finding a quantum spin liquid state in terms of destabilizing the ordered states by locating the spins on geometrically frustrated lattices such as Kagome, triangular, pyrochlore, and face centered cubic. Although it is an essential feature, frustration is a guide to help select systems that may be reasonable candidates for quantum spin liquids. Another approach is to look at systems in the metallic state. A quantum spin liquid can be thought of as a intermediate state between a paramagnetic metal and an ordered antiferromagnet. When magnetic ordering is suppressed, the liquid state of spins may be induced.
Heavy fermion and Quantum Criticality
Heavy fermion compounds are one of the most strongly correlated electronic systems and give rise to low temperature states that range from long-range magnetic order to exotic superconductivity, both of which are often in close proximity to quantum critical points. These strong electronic correlations are associated with the transfer of entropy from the local moment degrees of freedom to the conduction electrons. We are focusing on exploring and harnessing quantum criticality, with particular emphasis on the role of magnetic frustration. In Kondo lattice systems, rich behavior can be driven by magnetic frustration, which promotes complex ordering and might lead to a quantum spin liquid state under some circumstances.
Topologically Nontrivial States of Matter
Since the discovery of topological insulators and Dirac and Weyl semimetals, much research has focused on predicting and experimentally discovering distinct classes of these materials, in which the topology of electronic states leads to robust surface states and electromagnetic responses. Although theoretical analysis has provided valuable guidelines, the search for realistic materials remains a challenge.
Exploratory Synthesis of Quantum Materials
Discovering new quantum behavior has often been the outcome of a new material. Our research program on the growth and characterization of new materials has the potential to significantly impact progress in this area. If new compounds are synthesized, new properties could be found, leading toward to new direction of research such as unconventional superconductors, materials for quantum computing, and energy related materials (high performance magnets or thermoelectric materials).