Public Research Seminar by Advanced Materials Thrust, Function Hub, HKUST(GZ) - Exploring Novel Quantum Materials: Synthesis Strategies and Investigative Insights
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Quantum materials manifest the remarkable effects of quantum mechanics, giving rise to exotic and astonishing properties. The synthesis of high-quality quantum materials and the discovery of novel ones are very important for the scientific community to comprehend their fundamental behavior. In this seminar, I will delve into research strategies to uncover new or high-quality quantum materials through experimental approaches. This investigative process has yielded fruitful results.
The first example under scrutiny is Bismuth halides. By employing flip-CVT methods, high-quality and large size Bi4I4 and Bi4Br4 have been demonstrated, which presents challenges to synthesis using conventional techniques. These quasi-one-dimensional systems are an ideal system to investigate the suggested weak and high order topological insulator behaviors, owing to their weak interlayer coupling, large intrinsic gap, band simplicity and multiple cleavage surfaces. Additionally, multiple new polymorphic phases in this family are discovered via the doping induced layer stacking change. These new phases show intuiting physics, as evidenced by theory support, transport, scanning tuning microscopy and angle-resolved photoemission spectroscopy measurements.
The second example involves the high-pressure solid-vapor synthesis of 2D magnets CrSBr. Achieved under high Br pressure, high crystalline quality CrSBr shows remarkable properties, including high transition temperatures, high air-stability and strong light matter interactions. Through the research on magnetization, transport, specific heat, second harmonic generation (SHG), and among others, a three-stage magnetic ordering are recovered on bulk CrSBr. Moreover, an “extraordinary” surface magnetism has been revealed on CrSBr thin flakes. Expanding this synthesis strategy to other systems, I have discovered additional three new quantum materials, including a potential quantum spin liquid candidate and two new 1D magnets.
In the last, I will discuss several high-temperature superconductors synthesized under high pressure in the range of gigapascals.
Dr. Wenhao Liu is a research scientist in the physics department at the University of Texas at Dallas currently. He obtained his PhD from Nanjing University in 2018, where he focused on the exploration of novel superconducting materials synthesized under high pressure. He then joined King Abdullah University of Sci. and Tech. as a postdoctoral researcher, focusing on the nanofabrication of transition-metal-dichalcogenide materials. In 2019, he moved to the University of Texas at Dallas and expands his interest to high-quality quantum material synthesis and new material investigation. Currently his research focuses on developing new synthetic techniques to investigate new or high-quality quantum materials, including 2D magnets, superconductors, and topological nontrivial materials. He is also interested in investigating emergent and tunable properties of quantum materials via various methods such as synthetic route, pressure, doping and intercalation.