Complex magnetic ordering in the topological kagome metals RMn6Sn6

Following the recent discovery of a quantum-limit magnetic Chern phase in TbMn6Sn6, correlated topological metal RMn6Sn6 (R=Gd-Yb, and Y, Lu etc.), that possesses an ideal kagome lattice of Mn, has emerged as an exciting platform to explore the interplay between geometric frustration, non-trivial band topology and magnetism, as well as the resultant novel quantum phenomena. Inspired by the recent report of the anisotropically large THE and AHE in ErMn6Sn6, we propose to carry out the first single-crystal neutron diffraction studies of ErMn6Sn6 and similar TmMn6Sn6 at the time-of-flight diffractometer WISH, with a 7.5 or 10 T vertical-field cryomagnet.We believe that the new insights into the complex magnetic ordering and the interplay between the non-trivial topology and magnetism in this fascinating topological quantum material series can be obtained with the proposed experiments.