Robust kagome electronic structure in the topological quantum magnets XMn₆Sn₆ (X=Dy,Tb,Gd, Y) by Gu, X, Chen, C, Wei, WS, Gao, LL, Liu, JY, Du, X, Pei, D, Zhou, JS, Xu, RZ, Yin, ZX, Zhao, WX, Li, YD, Jozwiak, C, Bostwick, A, Rotenberg, E, Backes, D, Veiga, LSI, Dhesi, S, Hesjedal, T, Van Der Laan, G, Du, HF, Jiang, WJ, Qi, YP, Li, G, Shi, WJ, Liu, ZK, Chen, YL, Yang, LX