Electronic inhomogeneity at magnetic domain walls in strongly correlated systemsM. S. Rzchowski and R. Joynt
Physics Department, University of Wisconsin-Madison Madison, WI 53706, USA
(Received 16 January 2004; accepted in final form 3 May 2004)
We show that nano-scale variations of the order parameter in strongly correlated systems can induce local spatial regions such as domain walls that exhibit electronic properties representative of a different, but nearby, part of the phase diagram. This is done by means of a Landau-Ginzburg analysis of a metallic ferromagnetic system near an antiferromagnetic phase boundary. The strong spin gradients at a wall between domains of different spin orientation drive the formation of a new type of domain wall, where the central core is an insulating antiferromagnet, and connects two metallic ferromagnetic domains. We calculate the charge transport properties of this wall, and find that its resistance is large enough to account for recent experimental results in colossal magnetoresistance materials. The technological implications of this finding for switchable magnetic media are discussed.
75.47.-m - Magnetotransport phenomena; materials for magnetotransport.
72.25.Mk - Spin transport through interfaces.
75.60.Ch - Domain walls and domain structure.
© EDP Sciences 2004