Fachgruppe Nanostrukturierte Materialien    

The rich anisotropic transport behaviour shown by ferromagnetic semiconductors arises from a complex interplay of their electronic density of states and magnetic response. Such behaviour promises to enable devices whose ability to manipulate information in the form of electronic spin goes well beyond the now ubiquitous spin-valve read heads of magnetoelectronics, and on a platform that is compatible with conventional complementary metal oxide semiconductor technology. Most ferromagnetic semiconductor devices so far have relied on the bulk anisotropic behaviour of their constituent layers. Recent improvements in lithographic patterning enable the fabrication of a novel class of devices in which the anisotropy of many individual elements can be independently engineered. Here we demonstrate the first such device consisting of two nanobars with mutually orthogonal easy axes linked by a constriction. It behaves as a non-volatile memory element, where information can be written by setting the relative orientation of the magnetization of the nanobars, and read by measuring the constriction resistance.