A quantum ruler for orbital magnetism in moire quantum matter

• 成果类型: Article
• 署名作者: Slot, M. R.; Maximenko, Y.; Haney, P. M.; Kim, S.; Walkup, D. T.; Strelcov, E.; Le, Son T.; Shih, E. M.; Yildiz, D.; Blankenship, S. R.; Watanabe, K.; Taniguchi, T.; Barlas, Y.; Zhitenev, N. B.; Ghahari, F.; Stroscio, J. A.
• 署名单位: National Institute of Standards & Technology (NIST) - USA; Georgetown University; University System of Maryland; University of Maryland College Park; University System of Maryland; University of Maryland College Park; National Institute for Materials Science; National Institute for Materials Science; Nevada System of Higher Education (NSHE); University of Nevada Reno; George Mason University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-13690
• DOI: 10.1126/science.adf2040
• 发表日期: 2023-10-06
• 页码: 81-+
• 关键词: superconductivity; BEHAVIOR; bands

摘要

For almost a century, magnetic oscillations have been a powerful quantum ruler for measuring Fermi surface topology. In this study, we used Landau-level spectroscopy to unravel the energy-resolved valley-contrasting orbital magnetism and large orbital magnetic susceptibility that contribute to the energies of Landau levels of twisted double-bilayer graphene. These orbital magnetism effects led to substantial deviations from the standard Onsager relation, which manifested as a breakdown in scaling of Landau-level orbits. These substantial magnetic responses emerged from the nontrivial quantum geometry of the electronic structure and the large length scale of the moire lattice potential. Going beyond traditional measurements, Landau-level spectroscopy performed with a scanning tunneling microscope offers a complete quantum ruler that resolves the full energy dependence of orbital magnetic properties in moire quantum matter.