Quantum Materials

Quantum materials include materials where electronic or magnetic properties originate from nontrivial quantum mechanics. They are significant to the second quantum evolution that is related to modern technologies, e.g., quantum computers, quantum networks and memory devices. The Gui lab is mainly working on design and synthesis of NEW quantum materials, such as superconductors, magnetic topological materials, quantum spin liquids etc., starting from chemical perspectives (crystal structure, chemical bonding etc.). Moreover, connecting these new quantum materials with real-life applications (quantum computers, memory chips, heterogeneous catalysis etc.) is another potential direction of our research. We utilize a variety of experimental techniques, such as solid-state synthesis, crystal growth, powder/single crystal X-ray diffraction, powder/single crystal neutron diffraction, magnetic properties/electrical transport/heat capacity measurements etc. together with density-functional theory (DFT) calculations to achieve our research goals. Meanwhile, we aim to translate the physics of quantum materials into chemical language and bridge solid-state chemistry with other related fields.
New Superconductors and Their Applications to Future Quantum Computers

Superconductors produce zero electrical resistance and magnetic flux expulsion. Various alloys, intermetallics and oxides were found to be superconducting since the first discovery of superconductivity in Hg over a century ago. Regardless of differences in their formulas, a prominent similarity of them is their layered crystal structures. On the other hand, superconducting qubits for quantum computers have become the leading candidate for scalable quantum computers due to its high designability and scalability, and high feasibility to couple and control. It is promising that novel superconductors with appropriate properties can pave the way for better multi-qubit processors.
New Material Systems for Quantum Spin Liquid Candidates

Magnetic materials with magnetic atoms in one-dimensional (1-D) or two-dimensional (2-D) sublattices are of great interest to date. With 1-D or special 2-D lattices, i.e., linear chain, honeycomb, triangular and Kagome lattices, materials can exhibit frustrated magnetism which can potentially host quantum spin liquid state, a type of special quantum state that can never be magnetically ordered and has potential to be applied to quantum computers and is believed to relate to high-Tc superconductivity. These special structural motifs bring infinite opportunities for us to design/synthesize novel frustrated magnets/quantum spin liquids.
New Magnetic Topological Materials for Spintronic Devices

Topological materials are those where the properties on the surface are different than in the bulk. Because of the special properties, they can be extensively applied, such spintronic devices, i.e., memory devices. In the recent decade, people found that instead of looking for good ferromagnetic semiconductors, which is a hard task so far, antiferromagnetic (AFM) materials can be another great choice. On the other hand, another new emerging direction is spin-orbit torque on topological semimetals because its Dirac quasiparticles observed at Fermi energy can lead to highly efficient spintronic devices. Thus, looking for novel AFM topological semimetals for future spintronic devices are of great interests and this is a field where solid-state chemists can contribute to.
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