Drastic magnetic-field-induced chiral current order and emergent current-bond-field interplay in kagome metals

• 成果类型: Article
• 署名作者: Tazai, Rina; Yamakawa, Youichi; Kontani, Hiroshi
• 署名单位: Kyoto University; Nagoya University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11913
• DOI: 10.1073/pnas.2303476121
• 发表日期: 2024-01-16
• 关键词: superconductivity; MODEL

摘要

In kagome metals, the chiral current order parameter eta with time-reversal-symmetry-breaking is the source of various exotic electronic states, while the method of controlling the current order and its interplay with the star-of-David bond order phi are still unsolved. Here, we reveal that tiny uniform orbital magnetization M-orb[eta, phi] is induced by the chiral current order, and its magnitude is prominently enlarged under the presence of the bond order. Importantly, we derive the magnetic-field (h(z))-induced Ginzburg-Landau (GL) free energy expression Delta F [h(z), eta, phi] / h(z)M(orb) [eta, phi], which enables us to elucidate the field-induced current-bond phase transitions in kagome metals. The emergent current-bond-hz trilinear coupling term in the free energy, -m(1)h(z) eta center dot phi, naturally explains the characteristic magnetic-field sensitive electronic states in kagome metals, such as the field-induced current order and the strong interplay between the bond and current orders. The GL coefficients of Delta F [hz, eta, phi] derived from the realistic multiorbital model are appropriate to explain various experiments. Furthermore, we discuss the field-induced loop current orders in the square lattice models that have been studied in cuprate superconductors.