Spectroscopic detection of Dirac and Weyl fermions in real materials is vital for both, promising applications and fundamental bridge between high-energy and condensed-matter physics. While the presence of Dirac and noncentrosymmetric Weyl fermions is well established in many materials, the magnetic Weyl semimetals still escape direct experimental detection. In order to find a time-reversal symmetry breaking Weyl state we design two materials and present here experimental and theoretical evidence of realization of such a state in one of them, YbMnBi 2 . We model the time-reversal symmetry breaking observed by magnetization and magneto-optical microscopy measurements by canted antiferromagnetism and find a number of Weyl points. Using angle-resolved photoemission, we directly observe two pairs of Weyl points connected by the Fermi arcs. Our results not only provide a fundamental link between the two areas of physics, but also demonstrate the practical way to design novel materials with exotic properties.

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A new technique for contrast separation in wide-field magneto-optical Kerr microscopy is introduced. Utilizing the light from eight light emitting diodes, guided to the microscope by glass fibers and being switched synchronously with the camera exposure, domain images with orthogonal inplane sensitivity can be displayed simultaneously at real-time and images with pure in-plane or polar contrast can be obtained. The benefit of this new method of contrast separation is demonstrated for permalloy films, a NdFeB sinter magnet, and a cobalt crystal. Moreover, the new technique is shown to strongly enhance the sensitivity of Kerr microscopy by eliminating parasitic contrast contributions occurring in conventional setups. A doubling of the in-plane domain contrast and a sensitivity to Kerr rotations as low as 0.6 mdeg is demonstrated

Metallic glasses (MGs) inherit their amorphous structure from the liquid state, which predetermines their ability to withstand high loads approaching the theoretical limit. However, the absence of slip systems makes them very sensitive to the type of loading and extremely brittle in tension. The latter can be improved by precipitation of ductile crystals, which suppress a catastrophic propagation of shear bands in a glassy matrix. Here we report a novel approach to obtain MG-matrix composites with tensile ductility by flash Joule heating applied to Cu47.5Zr47.5Al5 (at.%) metallic glass. This homogeneous, volumetric and controllable rapid heat treatment allows achieving uniformly distributed metastable B2 CuZr crystals in the glassy matrix. It results in a significant tensile strain of 6.8±0.5%. Moreover, optimized adjustment of the heat-treatment conditions enables tuning of microstructure to achieve desired mechanical properties.

actuation devices. [1,2] The electric currentinduced switching of magnetization is one approach, but requires large spin polarized currents. For energy efficient operation, however, the involved dissipative electric currents should be minimal. The electric field control of magnetism is a promising low-power alternative, and increasing research efforts in this direction resulted in the discovery of various mechanisms in single-and two-phase multiferroics, magnetic semiconductors, and at gated metal surfaces allowing for voltage control of magnetic properties. [2,3] The exchange bias (EB), discovered decades ago, became an important property in modern thin-film magnetism, as it offers an elegant way to prepare thermally stable artificial domains and electrodes with a predefined macroscopic magnetization alignment. [4,5] The EB is manifested by a shift of the hysteresis curve of the ferromagnetic layer along the magnetic field axis and is based on a quantum mechanical exchange interaction occurring at the common interface between a thin ferromagnetic (FM) and antiferromagnetic (AFM) layer. EB thin films are extensively used to control the direction of magnetization in magnetic memories, spintronic, and magnetophoretic devices. [6] In the latter, for example, in-plane EB systems are utilized to generate artificial magnetic domain patterns and associated reconfigurable magnetic stray field landscapes, which can be used to locally guide the motion of magnetic micro-and nanoparticles. [7] Consequently, tailoring and control of EB has become a central objective in these research branches. Chemical, mechanical, thermal, and light ion bombardment-based techniques have been developed to tailor the EB, mainly by introducing irreversible material modifications at the AFM/ FM interface, for example, by changing the interface roughness or incorporating impurities. [8] The modification of the EB is not reversible for all of these methods. Moreover, most of them require an additional magnetic field and a sophisticated apparatus, such as vacuum equipment.The electric control of EB would provide an easily integrable alternative, ideally allowing for operando and reversible EB modification. Indeed, reversible control can be achieved by electric current-induced torque in the AFM layer, but Joule heating limits the energy-efficiency. [9] Alternative low power mechanisms for voltage-control of EB are therefore of great Electric manipulation of exchange bias (EB) systems is highly attractive for the development of modern spintronic and magnetophoretic devices. To date, electric control of the EB has mainly been based on multiferroic or resistive switching behavior in specific antiferromagnets, which limits the material choice and accessible EB states. In addition, the effects are mostly volatile, requiring constant voltage application. The continuous and nonvolatile tuning of the EB via electrochemical manipulation of the ferromagnetic layer is presented. In FeO x /Fe/IrMn systems, large changes in the EB field of fully shifted magneti...

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