Mesoscopic anisotropic magnetoconductance fluctuations in ferromagnets

The conductance of a ferromagnetic particle depends on the relative orientation of the magnetization with respect to the direction of current flow. This phenomenon is known as “anisotropic magnetoresistance.” Quantum interference leads to an additional random dependence of the conductance on the magnetization direction. These “mesoscopic anisotropic magnetoresistance fluctuations” are caused by the interplay of random impurity scattering and spin-orbit scattering, which couples the electron motion to the exchange field in the ferromagnet. We report a calculation of the dependence of the conductance autocorrelation function on the rotation angle of the magnetization direction.

Figure 1

Dyson equation for the Diffuson ladder. The dotted line indicates a scattering event.

Figure 2

(Color online) The correlation function of the conductance at different directions of the magnetization, for various strengths of the spin-orbit scattering. Results shown here are for a half metal with cubic geometry.