Manipulation of magnetization in GaMnAs films by spin-orbitinduced magnetic fields

다국어 초록 (Multilingual Abstract)

We have investigated the effect of spin-orbit-induced (SOI) magnetic fields on magnetization switching in GaMnAs films. The sign of such SOI fields depends on the direction of the current flowing in the film, thus providing a handle for electrically manipulating magnetization in ferromagnetic GaMnAs films. Specifically, when an applied magnetic field is swept along the current direction, magnetization reversal occurs via rotations in opposite sense (i.e., clockwise (CW) or counterclockwise (CCW)) depending on the sign of the current, thus leading to opposite signs of the planar Hall resistance (PHR) measured on the film. The effect of SOI fields also manifests itself through hysteretic behavior of PHR for two opposite currents as a fixed magnetic field is rotated in the film plane. The width of the resulting hysteresis between two current directions then allows us to estimate the magnitude of the SOI field at current density of 1.0 105 A/cm2 as ~1.2 Oe in our GaMnAs film. Such switching of magnetization between two magnetic easy axes induced by switching the sign of an applied current provides a means of electronically controlling the value of film resistance (in this case of PHR), a process that can be exploited in spintronic devices.

참고문헌 (Reference)

1 Z.T. Diao, "Spin-transfer torque switching in magnetic tunnel junctions and spin-transfer torque random access memory" 19 : 2007

2 D. Apalkov, "Spin-transfer torque magnetic random access memory (STT-MRAM)" 9 : 2013

3 A.R. Mellnik, "Spin-transfer torque generated by a topological insulator" 511 : 449-, 2014

4 L. Q. Liu, "Spin-torque switching with the giant spin Hall effect of tantalum" 336 : 555-558, 2012

5 D. C. Ralph, "Spin transfer torques" 320 : 1190-1216, 2008

6 S. M. Mohseni, "Spin torque-generated magnetic droplet solitons" 339 : 1295-1298, 2013

7 J. Curiale, "Joule heating and currentinduced domain wall motion" 112 : 2012

8 A. Chernyshov, "Evidence for reversible control of magnetization in a ferromagnetic material by means of spin-orbit magnetic field" 5 : 656-659, 2009

9 A. Yamaguchi, "Effect of Joule heating in current-driven domain wall motion" 86 : 2005

10 J. E. Wegrowe, "Currentinduced magnetization reversal in magnetic nanowires" 45 : 626-632, 1999

11 E. B. Myers, "Current-induced switching of domains in magnetic multilayer devices" 285 : 867-870, 1999

12 I. M. Miron, "Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer" 9 : 230-234, 2010

13 M. Endo, "Current induced effective magnetic field and magnetization reversal in uniaxial anisotropy (Ga,Mn)As" 97 : 2010

14 Y.Y. Li, "Anisotropic current-controlled magnetization reversal in the ferromagnetic semiconductor (Ga,Mn)As" 103 : 2013

15 E. Chen, "Advances and future prospects of spin-transfer torque random access memory" 46 : 1873-1878, 2010

16 M. Hosomi, "A novel nonvolatile memory with spin torque transfer magnetization switching:spin-RAM" 2005

17 K. Okamoto, "A new method for analysis of magnetic anisotropy in films using the spontaneous Hall effect" 35 : 353-355, 1983