Universal Ratio of Intrinsic Resistivities of Spin Helix in B20   (Fe-Co)Si Magnets
  The B20 magnets with the Dzyaloshinskii-Moriya (D-M) interaction exhibit spin helix and Skyrmion spin textures unattainable in traditional Heisenberg ferromagnets. We have determined the intrinsic resistivity of the spin helix, which is a macroscopic Bloch domain wall, in B20 (Fe-Co)Si magnets. We found a universal resistance ratio of gamma = 1.35 with current parallel and perpendicular to the helix, independent of composition and temperature. This gamma value is much smaller than 3, the well-known minimum value for domain wall resistivity in traditional ferromagnets, due to the significant spin-orbit coupling in the B20 magnets. 
S. X. Huang, Jian Kang, Fei Chen, Jiadong Zang, G. J. Shu, F. C. Chou,   S. V. Grigoriev, V. A. Dyadkin, and C. L. Chien
cond-mat.mtrl-sci cond-mat.str-el