Large topological Hall effect in a short-period helimagnet MnGe

Phys Rev Lett. 2011 Apr 15;106(15):156603. doi: 10.1103/PhysRevLett.106.156603. Epub 2011 Apr 15.


We have observed an unconventional, likely topological, Hall effect over a wide temperature region in the magnetization process of a chiral-lattice helimagnet MnGe. The magnitude of the topological Hall resistivity is nearly temperature-independent below 70 K, which reflects the real-space fictitious magnetic field proportional to a geometric quantity (scalar spin chirality) of the underlying spin texture. From the neutron diffraction study, it is anticipated that a relatively short-period (3-6 nm) noncoplanar spin structure is stabilized from the proper screw state in a magnetic field to produce the largest topological Hall response among the B20-type (FeSi-type) chiral magnets.