DAWN is a generic data analysis software platform that has been developed for use at synchrotron beamlines for data visualization and analysis. Its generic design makes it suitable for use in a range of scientific and engineering applications.

Magnetic skyrmions are chiral spin textures that hold great promise as nanoscale information carriers. Since their first observation at room temperature, progress has been made in their currentinduced manipulation, with fast motion reported in stray-field-coupled multilayers. However, the complex spin textures with hybrid chiralities and large power dissipation in these multilayers limit their practical implementation and the fundamental understanding of their dynamics. Here, we report on the current-driven motion of Néel skyrmions with diameters in the 100-nm range in an ultrathin Pt/Co/MgO trilayer. We find that these skyrmions can be driven at a speed of 100 m s −1 and exhibit a drive-dependent skyrmion Hall effect, which is accounted for by the effect of pinning. Our experiments are well substantiated by an analytical model of the skyrmion dynamics as well as by micromagnetic simulations including material inhomogeneities. This good agreement is enabled by the simple skyrmion spin structure in our system and a thorough characterization of its static and dynamical properties.

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We probe the current-induced magnetic switching of insulating antiferromagnet/heavy metals systems, by electrical spin Hall magnetoresistance measurements and direct imaging, identifying a reversal occurring by domain wall (DW) motion. We observe switching of more than one third of the antiferromagnetic domains by the application of current pulses. Our data reveal two different magnetic switching mechanisms leading together to an efficient switching, namely the spin-current induced effective magnetic anisotropy variation and the action of the spin torque on the DWs. 2 MANUSCRIPTElectrical read-out and writing of the antiferromagnetic state is crucial to exploit the properties of antiferromagnets in future spintronic devices. Antiferromagnetic materials have the potential for ultrafast operation [1], with spin dynamics in the terahertz range, high packing density, due to the absence of stray magnetic fields, and an insensitivity to magnetic fields [2,3]. Furthermore, low-power operation is possible in antiferromagnetic insulators (AFM-Is) due to long spin diffusion lengths [4] and the theoretical prediction of superfluid spin transport [5].Recently, the electrical reading of the Néel order (n) orientation in AFM-Is was demonstrated via spin Hall magnetoresistance (SMR) [6-10], a magnetoresistive effect depending on the mutual orientation of the magnetic order and an interfacial spin accumulation μs. However, one of the main challenges faced by AFM spintronics is the reliable electrical writing of the orientation of n. One possible approach exploits staggered Néel spin orbit torques [11], creating an effective field of opposite sign on each magnetic sublattice. However, these torques rely on special material requirements, which has limited their application to the conducting AFMs CuMnAs and Mn2Au [12][13][14][15][16]. Another approach would be to use the non-staggered, antidamping-like torque exerted by a spin accumulation at the interface of a heavy metal and an AFM-I. A charge current in the heavy metal layer can generate a transverse spin current via the spin Hall effect, creating antidamping-like torques in the antiferromagnet.The possibility of such switching was demonstrated in NiO(001)/Pt and Pt/NiO(111)/Pt [17,18], but the mechanisms are still debated. One of the possible mechanisms relies on spin-current induced domain wall (DW) motion [19], predicting that DWs with opposite chirality are driven in opposite directions, thus excluding the electrical signature of the switching when DWs with opposite chirality are equally probable. A second mechanism [18], based on the coherent rotation of n, predicts a current threshold ten times larger than that found experimentally. A third mechanism, based on field-like torques acting on uncompensated interfacial spins, requires perfectly flat interfaces [17]. Currently, none of these provides a consistent explanation of the effect.In this work we realize reliable current-induced switching in epitaxial antiferromagnetic NiO/Pt bilayers. We show that the magnetic state of ...

The magnetic order in antiferromagnetic materials is hard to control with external magnetic fields. Using X-ray Magnetic Linear Dichroism microscopy, we show that staggered effective fields generated by electrical current can induce modification of the antiferromagnetic domain structure in microdevices fabricated from a tetragonal CuMnAs thin film. A clear correlation between the average domain orientation and the anisotropy of the electrical resistance is demonstrated, with both showing reproducible switching in response to orthogonally applied current pulses. However, the behavior is inhomogeneous at the submicron level, highlighting the complex nature of the switching process in multi-domain antiferromagnetic films.Antiferromagnetic (AF) materials are of increasing interest both for fundamental physics and applications. Recent advances in detecting and manipulating AF order electrically have opened up new prospects for these materials in basic and applied spintronics research [1][2][3][4][5][6][7]. Of particular interest is the Néel order spin-orbit torque (NSOT) [6], recently demonstrated in the collinear AF CuMnAs [7], where a current-induced local spin polarization can exert a rotation of the magnetic sublattices. NSOT is closely analogous to the spin-orbit torque in ferromagnets with broken inversion symmetry, in which electrical currents induce effective magnetic fields that can be used to switch the magnetization direction [8,9]. The tetragonal CuMnAs lattice [10] is inversion symmetric, so that zero net spin polarization is generated by a uniform electric current. However, its Mn spin sublattices form inversion partners, resulting in local effective fields of opposite sign on the AF-coupled Mn sites [6,11]. These staggered current-induced fields can be large enough to cause a non-volatile rotation of the AF spin axis [7].Current-induced rotations of AF moments can be detected electrically using anisotropic magnetoresistance (AMR), a dependence on the relative orientation of the current and spin axes which is present in both ferromagnetic and AF materials [12][13][14][15]. This provides only spatially averaged information over the probed area of the device, which may be several microns or larger. PhotoEmission Electron Microscopy (PEEM), with contrast enabled by X-ray Magnetic Linear Dichroism (XMLD), provides direct imaging of AF domains with better than 100 nm resolution [16]. Based on differences in absorption of x-rays with linear polarization, XMLD-PEEM has offered valuable insights into the microscopic magnetic properties of AF films [17] and ferromagnet / AF interfaces [18,19]. The measured intensity varies as I 0 + I 2 cos 2 α, where α is the angle between the x-ray polarization and the spin axis [20], so is equally present for AF and FM materials, similar to AMR. The XMLD amplitude given by I 2 also depends on the orientation of the x-ray polarization with respect to the crystalline axes [21,22], and the signal is sensitive to domains within the top few nanometers of the surface.Here, we combin...