Quantum oscillations evidence for topological bands in kagome metal ScV(6)Sn(6).

Metals with kagome lattice provide bulk materials to host both the flat-band and Dirac electronic dispersions. A new family of kagome metals is recently discovered inAV6Sn6. The Dirac electronic structures of this material needs more experimental evidence to confirm. In the manuscript, we investigate this problem by resolving the quantum oscillations in both electrical transport and magnetization in ScV6Sn6. The revealed orbits are consistent with the electronic band structure models. Furthermore, the Berry phase of a dominating orbit is revealed to be aroundπ, providing direct evidence for the topological band structure, which is consistent with calculations. Our results demonstrate a rich physics and shed light on the correlated topological ground state of this kagome metal.

Zheng G ，Zhu Y ，Mozaffari S ，Mao N ，Chen KW ，Jenkins K ，Zhang D ，Chan A ，Arachchige HWS ，Madhogaria RP ，Cothrine M ，Meier WR ，Zhang Y ，Mandrus D ，Li L ... -  《-》

Dirac fermions and flat bands in the ideal kagome metal FeSn.

Kang M ，Ye L ，Fang S ，You JS ，Levitan A ，Han M ，Facio JI ，Jozwiak C ，Bostwick A ，Rotenberg E ，Chan MK ，McDonald RD ，Graf D ，Kaznatcheev K ，Vescovo E ，Bell DC ，Kaxiras E ，van den Brink J ，Richter M ，Prasad Ghimire M ，Checkelsky JG ，Comin R ... -  《-》

Dirac cone, flat band and saddle point in kagome magnet YMn(6)Sn(6).

Li M ，Wang Q ，Wang G ，Yuan Z ，Song W ，Lou R ，Liu Z ，Huang Y ，Liu Z ，Lei H ，Yin Z ，Wang S ... -  《Nature Communications》

Emergent topological quantum orbits in the charge density wave phase of kagome metal CsV(3)Sb(5).

The recently discovered kagome materials AV3Sb5 (A = K, Rb, Cs) attract intense research interest in intertwined topology, superconductivity, and charge density waves (CDW). Although the in-plane 2 × 2 CDW is well studied, its out-of-plane structural correlation with the Fermi surface properties is less understood. In this work, we advance the theoretical description of quantum oscillations and investigate the Fermi surface properties in the three-dimensional CDW phase of CsV3Sb5. We derived Fermi-energy-resolved and layer-resolved quantum orbits that agree quantitatively with recent experiments in the fundamental frequency, cyclotron mass, and topology. We reveal a complex Dirac nodal network that would lead to a π Berry phase of a quantum orbit in the spinless case. However, the phase shift of topological quantum orbits is contributed by the orbital moment and Zeeman effect besides the Berry phase in the presence of spin-orbital coupling (SOC). Therefore, we can observe topological quantum orbits with a π phase shift in otherwise trivial orbits without SOC, contrary to common perception. Our work reveals the rich topological nature of kagome materials and paves a path to resolve different topological origins of quantum orbits.

Tan H ，Li Y ，Liu Y ，Kaplan D ，Wang Z ，Yan B ... -  《npj Quantum Materials》

Massive Dirac fermions in a ferromagnetic kagome metal.

Ye L ，Kang M ，Liu J ，von Cube F ，Wicker CR ，Suzuki T ，Jozwiak C ，Bostwick A ，Rotenberg E ，Bell DC ，Fu L ，Comin R ，Checkelsky JG ... -  《-》