Antiferromagnetic real-space configuration probed by dichroism in scattered x-ray beams with orbital angular momentum

X-ray beams with orbital angular momentum (OAM) are a promising tool for x-ray characterization techniques. Beams OAM have helicity--an azimuthally varying phase--which leads to gradient of the light field. New material properties can be probed by utilizing helicity an beam. Here, we demonstrate novel dichroic effect in resonant diffraction from artificial antiferromagnet topological defect. We found that scattered beam has circular dichroism at antiferromagnetic Bragg peak whose sign is coupled its helicity, which reveals real-space configuration ground state. Thermal cycling change state, as indicated reversal dichroism. This result one first demonstrations soft spectroscopy technique x-rays. helicity-dependent exemplifies potential utilize probe matter way inaccessible using currently available