Microcircuit tailoring in ferromagnetic semiconductor (Ga,Mn)As
In order to search for novel giant-magnetoresistance systems, we fabricated and investigated narrow constrictions in the layers of the ferromagnetic semiconductor (Ga,Mn)As. We found that constrictions a few hundred nanometers wide, tailored by means of the electron-beam lithography and wet etching, were not conducting at liquid helium temperatures unless illuminated, probably due to the trapping