Spin–orbit torque magnetization switching is an efficient method to control magnetization. In perpendicularly magnetized films, two types of spin–orbit torque are induced by driving a current: a damping-like torque and a field-like torque. The damping-like torque assists magnetization switching, but a large field-like torque pushes the magnetization towards the in-plane direction, resulting in a larger critical switching current density and making deterministic switching challenging. Control of the field-like torque strength is difficult because it is intrinsic to the material system used. Here, we show that the field-like term can be suppressed in a spin–orbit ferromagnetic single layer of (Ga,Mn)As by a current-induced Oersted field due to its non-uniform current distribution, making the damping-like torque term (the result of strong Dresselhaus spin–orbit coupling) dominant. The Oersted field can be controlled by the film thickness, resulting in an extremely low switching current density of 4.6 × 104 A cm–2. This strategy can thus provide an efficient approach to spin–orbit torque magnetization switching.
Subscribe to Journal
Get full journal access for 1 year
only $8.25 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Liu, L., Lee, O. J., Gudmundsen, T. J., Ralph, D. C. & Buhrman, R. A. Current-induced switching of perpendicularly magnetized magnetic layers using spin torque from the spin Hall effect. Phys. Rev. Lett. 109, 096602 (2012).
Shi, G. Y. et al. Spin-orbit torque in MgO/CoFeB/Ta/CoFeB/MgO symmetric structure with interlayer antiferromagnetic coupling. Phys. Rev. B 95, 104435 (2017).
Liu, L. et al. Spin-torque switching with the giant spin Hall effect of tantalum. Science 336, 555–558 (2012).
Miron, I. M. et al. Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection. Nature 476, 189–193 (2011).
Emori, S., Bauer, U., Ahn, S. M., Martinez, E. & Beach, G. S. D. Current-driven dynamics of chiral ferromagnetic domain walls. Nat. Mater. 12, 611–616 (2013).
Myers, E. B., Ralph, D. C., Katine, J. A., Louie, R. N. & Buhrman, R. A. Current-induced switching of domains in magnetic multilayer devices. Science 285, 867–870 (1999).
An, H., Kageyama, Y., Kanno, Y., Enishi, N. & Ando, K. Spin–torque generator engineered by natural oxidation of Cu. Nat. Commun. 7, 13069 (2016).
Jiang, M. et al. Efficient full spin–orbit torque switching in a single layer of a perpendicularly magnetized single-crystalline ferromagnet. Nat. Commun. 10, 2590 (2019).
Khang, N. H. D., Ueda, Y. & Hai, P. N. A conductive topological insulator with large spin Hall effect for ultralow power spin–orbit torque switching. Nat. Mater. 17, 808–813 (2018).
Hai, P. N., Nguyen, H. D. K., Yao, K. & Ueda, Y. Conductive BiSb topological insulator with colossal spin Hall effect for ultra-low power spin-orbit-torque switching. Proc. SPIE 10732, 107320U (2018).
Han, J. et al. Room-temperature spin-orbit torque switching induced by a topological insulator. Phys. Rev. Lett. 119, 077702 (2017).
Fan, Y. et al. Magnetization switching through giant spin–orbit torque in a magnetically doped topological insulator heterostructure. Nat. Mater. 13, 699–704 (2014).
Chernyshov, A. et al. Evidence for reversible control of magnetization in a ferromagnetic material by means of spin–orbit magnetic field. Nat. Phys. 5, 656–659 (2009).
Kurebayashi, H. et al. An antidamping spin–orbit torque originating from the Berry curvature. Nat. Nanotechnol. 9, 211–217 (2014).
Fang, D. et al. Spin–orbit-driven ferromagnetic resonance. Nat. Nanotechnol. 6, 413–417 (2011).
Ohya, S., Takata, K. & Tanaka, M. Nearly non-magnetic valence band of the ferromagnetic semiconductor GaMnAs. Nat. Phys. 7, 342–347 (2011).
Endo, M., Matsukura, F. & Ohno, H. Current induced effective magnetic field and magnetization reversal in uniaxial anisotropy (Ga,Mn)As. Appl. Phys. Lett. 97, 222501 (2010).
Lee, S. et al. Field-free manipulation of magnetization alignments in a Fe/GaAs/GaMnAs multilayer by spin-orbit-induced magnetic fields. Sci. Rep. 7, 10162 (2017).
Kobayashi, M. et al. Unveiling the impurity band induced ferromagnetism in the magnetic semiconductor (Ga,Mn)As. Phys. Rev. B 89, 205204 (2014).
Muneta, I., Ohya, S., Terada, H. & Tanaka, M. Sudden restoration of the band ordering associated with the ferromagnetic phase transition in a semiconductor. Nat. Commun. 7, 12013 (2016).
Muneta, I., Kanaki, T., Ohya, S. & Tanaka, M. Artificial control of the bias-voltage dependence of tunnelling-anisotropic magnetoresistance using quantization in a single-crystal ferromagnet. Nat. Commun. 8, 15387 (2017).
Campion, R. P. et al. The growth of GaMnAs films by molecular beam epitaxy using arsenic dimers. J. Cryst. Growth 251, 311–316 (2003).
Mathieu, R. et al. Magnetization of ultrathin (Ga,Mn)As layers. Phys. Rev. B 68, 184421 (2003).
Luo, J. et al. Uniform annealing effect of electron irradiation on ferromagnetic GaMnAs thin films. J. Magn. Magn. Mater. 422, 124–127 (2017).
Nagaosa, N., Sinova, J., Onoda, S., MacDonald, A. H. & Ong, N. P. Anomalous Hall effect. Rev. Mod. Phys. 82, 1539–1592 (2010).
Shi, G. et al. Spin–orbit torque switching in MgO/CoFeB/Ta/CoFeB/MgO heterostructures with a critical current density of 105 A/cm2. Jpn. J. Appl. Phys. 56, 100303 (2017).
This work was partly supported by Grants-in-Aid for Scientific Research (no. 16H02095 and no. 18H03860), the CREST program of the Japan Science and Technology Agency (JPMJCR1777), the Spintronics Research Network of Japan (Spin-RNJ) and the China Scholarship Council (no. 201706210086).
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Figs. 1–8, Discussion and Table 1.
Statistical source data for Supplementary Fig. 2.
Statistical source data for Supplementary Fig. 3.
Statistical source data for Supplementary Fig. 4.
Statistical source data for Supplementary Fig. 5.
Statistical source data for Supplementary Fig. 6.
Statistical source data for Supplementary Fig. 7.
Statistical source data for Supplementary Fig. 8.
About this article
Cite this article
Jiang, M., Asahara, H., Sato, S. et al. Suppression of the field-like torque for efficient magnetization switching in a spin–orbit ferromagnet. Nat Electron 3, 751–756 (2020). https://doi.org/10.1038/s41928-020-00500-w