Title: Spectroscopic Studies on the Superconducting Order Parameter and Competing Electronic Orders in Kagome Superconductors
Date and Time: November 15, 2024 (Friday) 10:30 AM
Venue: Fifth Conference Room, Building A, Science and Education Building, Feicuihu Campus
Presenter: Professor Wang Zhenyu
Affiliation: University of Science and Technology of China
Abstract:
Due to special geometric frustrations, two-dimensional kagome systems exhibit a series of emergent electronic orders near the Van Hove filling. The discovery of anomalous charge density waves, superconductivity, and pairing density waves in the kagome superconductor AVSb5(where A is an alkali metal) provides a promising experimental platform for exploring these phenomena. In this report, we will discuss the charge density wave (CDW) state in the kagome superconductor AVSb5 and its anomalous competition with superconductivity. We will show that, at low temperatures, the CDW state induces a novel three-state Potts electronic nematic phase. Using quasiparticle coherence scattering imaging, we reveal the impact of this electronic nematic phase on low-energy electronic excitations and discuss its interactions with superconductivity. Through Bogoliubov quasiparticle interference, we further construct the gap function of the superconducting state and find that it exhibits significant anisotropy, directly competing with the CDW gap in momentum space.
Presenter Bio:
Professor Wang Zhenyu completed his undergraduate studies at Wuhan University and obtained his Ph.D. from the Institute of Physics, Chinese Academy of Sciences. He then conducted postdoctoral research at the University of Illinois at Urbana-Champaign, USA. In 2019, he joined the University of Science and Technology of China, where he is currently a professor at the School of Physics. His main research focuses on studying the electronic behavior and underlying physical mechanisms in quantum materials using scanning tunneling microscopy/spectroscopy. He has made a series of research contributions in areas such as unconventional superconductivity, Mott transitions, and topological phases. As the first or corresponding author, he has published over 20 papers in journals including Nature, Science, Nature Physics (3 papers), Phys. Rev. X (2 papers), PNAS, and others.