Unusual magnetic and transport properties in HoMn$_6$Sn$_6$ kagome magnet

Abstract

With intricate lattice structures, kagome materials are an excellent platform to study various fascinating topological quantum states. In particular, kagome materials, revealing large responses to external stimuli such as pressure or magnetic field, are subject to special investigation. Here, we study the kagome-net HoMn6Sn6 magnet that undergoes paramagnetic to ferrimagnetic transition (below 376 K) and reveals spin-reorientation transition below 200 K. In this compound, we observe the topological Hall effect and substantial contribution of anomalous Hall effect above 100 K. We unveil the pressure effects on magnetic ordering at a low magnetic field from the pressure tunable magnetization measurement. By utilizing high-resolution angle-resolved photoemission spectroscopy, Dirac-like dispersion at the high-symmetry point K is revealed in the vicinity of the Fermi level, which is well supported by the first-principles calculations, suggesting a possible Chern-gapped Dirac cone in this compound. Our investigation will pave the way to understand the magneto-transport and electronic properties of various rare-earth-based kagome magnets.

Evolution of the Chern Gap in Kagome Magnet HoMn6Sn6−xGex

“…This work provides a theoretical investigation into the effect of changing one of the parameters in this highly tunable system and the effect that it has on Chern gap formation. The tin (Sn) atoms in HoMn 6 Sn 6 [44][45][46][47] are gradually doped with Germanium (Ge) HoMn 6 Sn 6−x Ge x (x = 0, 2, 4, 6) in order to see the effect on the bands structure. Interestingly, the Chern gap disappears with light doping and then forms two new stacked Chern gaps in HoMn 6 Ge 6 .…”

Spectroscopic evidence of flat bands in breathing kagome semiconductor Nb3I8

“…In recent times, it has been successful in revealing the electronic structure of various kagome materials. Topological Dirac bands and/or flat bands in the electronic structures of Fe 3 Sn 2 [4,18], FeSn [14], CoSn [12,13], RT 6 Sn 6 (R = Tb, Y, Er, Ho, Gd and T = Mn, V) [8,15,[25][26][27], CsV 3 Sb 5 [28] have been observed by utilizing ARPES. A point to note is that these materials are metals with conventional kagome lattice.…”