摘要
We investigated the effect of low temperature annealing on magnetic anisotropy in 7-nm ultrathin Ga0.94Mn0.06As devices by measuring the angle-dependent planar Hall resistance（PHR）.Obvious hysteresis loops were observed during the magnetization reversal through the clockwise and counterclockwise rotations under low magnetic fields（below 1000 Gs,1 Gs = 10-4 T）,which can be explained by competition between Zeeman energy and magnetic anisotropic energy.It is found that the uniaxial anisotropy is dominant in the whole measured ferromagnetic range for both the as-grown ultrathin Ga0.94Mn0.06As and the annealed one.The cubic anisotropy changes more than the uniaxial anisotropy in the measured temperature ranges after annealing.This gives a useful way to tune the magnetic anisotropy of ultrathin（Ga,Mn）As devices.
We investigated the effect of low temperature annealing on magnetic anisotropy in 7-nm ultrathin Ga0.94Mn0.06As devices by measuring the angle-dependent planar Hall resistance（PHR）.Obvious hysteresis loops were observed during the magnetization reversal through the clockwise and counterclockwise rotations under low magnetic fields（below 1000 Gs,1 Gs = 10-4 T）,which can be explained by competition between Zeeman energy and magnetic anisotropic energy.It is found that the uniaxial anisotropy is dominant in the whole measured ferromagnetic range for both the as-grown ultrathin Ga0.94Mn0.06As and the annealed one.The cubic anisotropy changes more than the uniaxial anisotropy in the measured temperature ranges after annealing.This gives a useful way to tune the magnetic anisotropy of ultrathin（Ga,Mn）As devices.
基金
Project supported by the National Basic Research Program of China (Grant No. 2011CB922200)
the National Natural Science Foundation of China (Grant No. 11174272)
the Engineering and Physical Sciences Research Council-National Natural Science Foundation Joint (Grant No.10911130232/A0402)
Wang Kai-You acknowledges support of the Chinese Academy of Sciences’"100 Talent Program."
