Unconventional magnetic oscillations in a kagome Mott insulator

• 成果类型: Article
• 署名作者: Zheng, Guoxin; Zhu, Yuan; Chen, Kuan-Wen; Kang, Byungmin; Zhang, Dechen; Jenkins, Kaila; Chan, Aaron; Zeng, Zhenyuan; Xu, Aini; Valenzuela, Oscar A.; Blawat, Joanna; Singleton, John; Li, Shiliang; Lee, Patrick A.; Li, Lu
• 署名单位: University of Michigan System; University of Michigan; Massachusetts Institute of Technology (MIT); Chinese Academy of Sciences; Institute of Physics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; United States Department of Energy (DOE); Los Alamos National Laboratory; Songshan Lake Materials Laboratory
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12007
• DOI: 10.1073/pnas.2421390122
• 发表日期: 2025-02-04
• 关键词: state

摘要

In metals, electrons in a magnetic field undergo cyclotron motion, leading to oscillations in physical properties called quantum oscillations. This phenomenon has never been seen in a robust insulator because there are no mobile electrons. We report an exception to this rule. We study a Mott insulator on a kagome lattice which does not order magnetically down to milli-Kelvin temperatures despite antiferromagnetic interactions. We observe a plateau at magnetization equal to 9 1Bohr magneton per magnetic ion, accompanied by oscillations in the magnetic torque, reminiscent of quantum oscillations in metals. The temperature dependence obeys Fermi distribution. These phenomena are consistent with a quantum spin liquid state whose excitations are fermionic spinons with a Dirac-like spectrum coupled to an emergent gauge field.