Intrinsic spin valves in the layered manganite La1.4Sr1.6Mn2O7 -: art. no. 012410

We report on low-temperature transport measurements on small mesa structures fabricated on single crystals of the layered manganite La1.4Sr1.6Mn2O7, with current perpendicular to die layers. The mesa thicknesses were less than 20 unit cells, and their lateral size was well below the size of a magnetic domain. In external magnetic fields perpendicular to the layers, switching of the magnetoresistance was observed in fields below 0.4 T, while for parallel fields it decreased continuously. We interpret these observations in terms of simultaneous switching of all natural spin valves contained in the mesa structure.