0000000000385608
AUTHOR
Huawei Gao
Relativistic Neel-order fields induced by electrical current in antiferromagnets
We predict that a lateral electrical current in antiferromagnets can induce non-equilibrium N\'eel order fields, i.e. fields whose sign alternates between the spin sublattices, which can trigger ultra-fast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intra-band and to the intrinsic inter-band spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we considered bulk Mn2Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry model…
Spin-orbit torques in locally and globally non-centrosymmetric crystals: Antiferromagnets and ferromagnets
One of the main obstacles that prevents practical applications of antiferromagnets is the difficulty of manipulating the magnetic order parameter. Recently, following the theoretical prediction [J. \v{Z}elezn\'y et al., PRL 113, 157201 (2014)], the electrical switching of magnetic moments in an antiferromagnet has been demonstrated [P. Wadley et al., Science 351, 587 (2016)]. The switching is due to the so-called spin-orbit torque, which has been extensively studied in ferromagnets. In this phenomena a non-equilibrium spin-polarization exchange coupled to the ordered local moments is induced by current, hence exerting a torque on the order parameter. Here we give a general systematic analys…
Disorder and localization effects on the local spectroscopic and infrared optical properties ofGa1−xMnxAs
We study numerically the influence of disorder and localization effects on the local spectroscopic characteristics and infrared optical properties of ${\text{Ga}}_{1\ensuremath{-}x}{\text{Mn}}_{x}\text{As}$. We treat the band structure and disorder effects at an equal level by using an exact diagonalization supercell simulation method. This method accurately describes the low-doping limit and gives a clear picture of the transition to higher dopings, which captures the localization effects inaccessible to other theoretical methods commonly used. Our simulations capture the rich in-gap localized states observed in scanning tunneling microscopy studies and reproduce the observed features of t…
Intraband and interband spin-orbit torques in noncentrosymmetric ferromagnets
Intraband and interband contributions to the current-driven spin-orbit torque in magnetic materials lacking inversion symmetry are theoretically studied using Kubo formula. In addition to the current-driven field-like torque ${\bf T}_{\rm FL}= \tau_{\rm FL}{\bf m}\times{\bf u}_{\rm so}$ (${\bf u}_{\rm so}$ being a unit vector determined by the symmetry of the spin-orbit coupling), we explore the intrinsic contribution arising from impurity-independent interband transitions and producing an anti-damping-like torque of the form ${\bf T}_{\rm DL}= \tau_{\rm DL}{\bf m}\times({\bf u}_{\rm so}\times{\bf m})$. Analytical expressions are obtained in the model case of a magnetic Rashba two-dimension…