Giant orbital moments are responsible for the anisotropic magnetoresistance of atomic contacts

被引:12
作者
Autes, G. [1 ]
Barreteau, C. [1 ]
Desjonqueres, M. C. [1 ]
Spanjaard, D. [2 ]
Viret, M. [3 ]
机构
[1] CEA, IRAMIS, SPCSI, F-91191 Gif Sur Yvette, France
[2] Univ Paris Sud, UMR 8502, Phys Solides Lab, F-91405 Orsay, France
[3] CEA, IRAMIS, SPEC, F-91191 Gif Sur Yvette, France
关键词
D O I
10.1209/0295-5075/83/17010
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We study here, both experimentally and theoretically, the anisotropy of magnetoresistance in atomic contacts. Our measurements on iron break junctions reveal an abrupt and hysteretic switch between two conductance levels when a large applied field is continuously rotated. We propose that this behaviour stems from the coexistence of two metastable electronic states which result from the anisotropy of electronic interactions responsible for the enhancement of orbital magnetization. In both states giant orbital moments appear on the low coordinated central atom in a realistic contact geometry. However, they differ by their orientation, parallel or perpendicular, with respect to the axis of the contact. Our explanation is totally at variance with the usual model based on the band structure of a monatomic linear chain, which we argue cannot be applied to 3d ferromagnetic metals. Copyright (C) EPLA, 2008.
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页数:5
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