1. Tunning anomalous Hall conductivity in L1(0) FePt films by chemical long range ordering
M. Chen, Z. Shi, S. M. Zhou
Surface Physics State Laboratory and Department of Physics, Fudan University, Shanghai , China
Abstract: Effect of spin orbit coupling on anomalous Hall conductivity (AHC) has for the first time been experimentally studied, by exploiting L1(0) FePt films. Contributions of the skew scattering and the side jump to the AHC change non-monotonically with chemical long range ordering S and the intrinsic one changes monotonically. They are all proportional to spontaneous magnetization MS. The spin orbit coupling strength is indicated to increase with increasing S. As a new approach, the AHC in ferromagnetic alloy films can be controlled by chemical long range ordering.
MgO(substrate)
FePt
rxx
rxy
The relationship of and
skew scattering
side jump and intrinsic
Figures 3(a) and 3(b) show that ao and bo change non-monotonically with S. For S = 0 and 0.86, ao approaches zero and has a minimal value at intermediate S. bo is equal to 700 (Ω cm)-1 for S = 0 and increases with a maximal value of 900 (Ωcm)-1, and finally approaches a saturation value of 600 (Ω cm)-1 for S = Opposite signs of ao and bo indicate that the skew scattering has contribution to the AHC in an opposite way to those of the side-jump and the Karplus-Luttinger terms.
According to Eq.72 in Ref.[2], σsko has a minimum at Δgap/vkF ≈ 0.5
with Δgap ∝ ξ2 and v being the model parameter.
σsjo obeys the ξ dependence similar to that of ao as shown by Eq.76 in Ref.[3]
and Eq.17 in Ref.[4], it also changes non-monotonically with S.
If is proportional to
reference:
[1] N. Nagaosa, arXiv 0904,4154v1
[2] N. A. Sinitsyn et al, Phys. Rev. B 75, (2007)
[3] P. Wölfle and K. A. Muttalib, Ann. Phys. (Leipzig), 15, 508 (2006)
[4] N. A. Sinitsyn, J. Phy. Condens. Matter, 20, (2008)