Chirality induced anomalous-Hall effect in helical spin crystals

Under pressure, the itinerant helimagnet MnSi displays unusual magnetic properties. We have previously discussed a bcc helical spin crystal as a promising starting point for describing the high pressure phenomenology. This state has topologically non-trivial configurations of the magnetization field. Here we note the consequences for magneto-transport that arise generally from such spin textures. In particular, a skyrmion density induced 'topological' Hall effect., with unusual field dependence, is described. (C) 2007 Elsevier B.V. All rights reserved.