Fig. 2: Chirality of the 7-SL edge states under opposite magnetization.
From: Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator
a and b Static magnetic flux images after the sample are magnetized under 9 T (a) and −9 T (b), respectively. The 7-SL region shows net M. c and d Current flux images corresponding to the magnetization in (a and b), respectively. A 500 nA AC current plus a 1 μA DC offset is applied to the right electrode. e and f Current flux images with the same current bias as in (c and d) but applied to the left electrode. All the current flux images are taken at \({V}_{{{\rm{g}}}}=50\,\)V. The streamlines are current flows around the 7-SL edge reconstructed from the current flux images. They show the edge current (\({I}_{{{\rm{l}}}}\) for the lower edge and \({I}_{{{\rm{u}}}}\) for the upper edge) and its chirality (magenta/+ for clockwise and blue/− for counter-clockwise), which predominantly carry the current under each configuration.
