The magnetoresistance tensor of La0.8Sr0.2MnO3

The interplay between spin polarized current and mag-netic moments gives rise to intriguing phenomena whichhave led to the emergence of the field of spintronics [1].In most cases, the materials used for studying these phe-nomena have been amorphous alloys of 3d itinerant fer-romagnets (e.g., permalloy), while much less is knownabout the behavior in materials which are crystalline andmore complicated. Manganites, which are magnetic per-ovskites, serve as a good example for such a system. Aswe will show, elucidating these phenomena in this ma-terial system provides tools for better theoretical under-standing of spintronics phenomena and reveals opportu-nities for novel device applications.The magnetotransport properties of manganitesknown for their colossal magnetoresistance have beenstudied quite extensively; nevertheless, along numerousstudies devoted to elucidating the role of the magni-tude of the magnetization, relatively few reports have ad-dressed the role of the orientation of the magnetization,which is known to affect both the longitudinal resistivityρ