Spin-dependent conductance across a manganate-barrier-manganate junction has
recently been demonstrated. The junction is a La0.67​Sr0.33​MnO3​%
-SrTiO3​-La0.67​ Sr0.33​MnO3​ trilayer device supporting
current-perpendicular transport. Large magnetoresistance of up to a factor of
five change was observed in these junctions at 4.2K in a relatively low field
of the order of 100 Oe. Temperature and bias dependent studies revealed a
complex junction interface structure whose materials physics has yet to be
understood.Comment: 20 pages, 14 figures. To appear in Phil. Trans. R. Soc. Lond. A
vol.356 (1998