Electron correlations and charge density wave in the topological kagome metal FeGe

Recently, a charge density wave was discovered in the magnetic binary kagome metal FeGe [1].

In analogy to its predecessor, the non-magnetic AV3Sb5 (A=K, Cs, Rb), the in-plane ordering

occurs at the M point. In contrast, however, the system manifestly shows effects of

substantial correlations. Here [2], we identify the topological bands crossing the Fermi energy in

FeGe and characterize the correlation-induced renormalization of these bands. We derive a

charge order from an effective model comprising topological kagome `flat' bands in the presence

of a magnetic order. We demonstrate edge states and excess out-of-plane magnetic moments

associated with the charge order; both are fingerprints of non-trivial band topology and

consistent with experimental observations [1,3]. Our results point to FeGe as an ideal platform to

realize and elucidate correlated topological physics.

Supported by the DOE BES Award # DE-SC0018197, LANL LDRD, UC Lab. Fees Research

Program, Quantum Science Center, a U.S. DOE Office of Science National QIS Research

Center, & CINT, a DOE BES user facility.

[1] X. Teng et al. Nature 609, 490 (2022)

[2] C. Setty et al., Electron correlations and charge density wave in the topological kagome metal

FeGe. arXiv:2203.01930.

[3] J. X. Yin et al., PRL 129, 166401 (2022)