Probing orbital magnetism of a kagome metal CsV3Sb5 by a tuning fork resonator
Hengrui Gui, Lin Yang, Xiaoyu Wang, Dong Chen, Zekai Shi, Jiawen Zhang, Jia Wei, Keyi Zhou, Walter Schnelle, Yongjun Zhang, Yu Liu, A. F. Bangura, Ziqiang Wang, Claudia Felser, Huiqiu Yuan, Lin Jiao
Abstract
The recently discovered kagome metal CsV3Sb5 exhibits a complex phase diagram that encompasses frustrated magnetism, topological charge density wave (CDW), and superconductivity. One CDW state that breaks time-reversal symmetry was proposed in this compound, while the exact nature of the putative magnetic state remains elusive. To examine the thermodynamic state of CsV3Sb5 and assess the character of the associated magnetism, we conducted tuning fork resonator measurements of magnetotropic susceptibility over a broad range of angles, magnetic fields, and temperatures. We found a cascade of phase transitions in the CDW phase. Of particular interest is a highly anisotropic magnetic structure that arises below about 30 K, with a magnetic moment along the c-axis that has an extremely small magnitude. This magnetic state demonstrates extremely slow dynamics and small saturate field, all suggest that electronic phase below 30 K breaks time reversal symmetry and has an unconventional origin. Using a tuning fork-based probe, the authors offer evidence of 2D magnetic moment along the c-axis of CsV3Sb5. Their findings suggest that loop currents within the kagome lattice can generate orbital magnetism.