1. Extrinsic Anomalous Hall Effect in Ni thin films
modified by 1 ML copper interface
Jianli Xu, Yufan Li, Dazhi Hou and Xiaofeng Jin
Surface Physics Laboratory and Physics Department, Fudan University, Shanghai , China
Ordinary Hall Effect
Anomalous Hall Effect
Sample preparation
MgO(001)
Ni(001)
1ML Cu
MgO
thickness
Intrinsic[1][2][3]: anomalous velocity produced by
band mixing and spin-orbit coupling
Extrinsic: skew scattering[4] and side jump[5]
induced by impurity scattering
ρ ah =α ρ xx0 +β ρ 2 xx0 +b ρ 2 xx
σ ah =−(α ρ xx0 +β ρ 2 xx0 ) σ 2 xx −b
[1]Karplus & Luttinger (1954)
[2]Jungwirth, Niu, MacDonald (2002)
[3]Onoda & Nagaosa (2002)
[4]J. Smit, Physica (1955); 24, 39 (1958).
[5]L. Berger, PRB 2, 4559 (1970).
RHEED pattern of substrate and sample
[6]Y. Tian, L. Ye, X.F. Jin, Phys. Rev. Lett., 103, (2009)
[7] L. Ye ,Y. Tian,,X.F. Jin, arXive: v1
What would happen for interface modification?
MgO(001) Epitaxial Ni(001)
Finite size effect
The AHE by interface modification
Short-circuit
maximum≈10%
Dominance of skew scattering
Determination of α
T=5K
𝛒 𝐚𝐡𝟎 𝛒 𝐱𝐱𝟎 =𝛂+(𝛃+𝐛) 𝛒 𝐱𝐱𝟎
𝝈 𝑺𝑲 =-𝜶 𝝆 𝒙𝒙𝟎 𝝈 𝟐 𝒙𝒙
Conclusion: The modification of Anomalous Hall effect in Ni film by inserting 1ML copper is apparently dominant by the skew scattering.