X-ray magnetic circular dichroism spectroscopy at the Fe L edges with a picosecond laser-driven plasma source
Time-resolved x-ray magnetic circular dichroism (XMCD) enables a unique spectroscopic view on complex spin and charge dynamics in multi-elemental magnetic materials. So far, its application in the soft-x-ray range has been limited to synchrotron-radiation sources and free-electron lasers. By combining a laser-driven plasma source with a magnetic thin-film polarizer, we generate up to 30% circular polarization in the soft-x-ray regime, enabling the first XMCD spectroscopy at the Fe 𝐿 edges in a laser laboratory, to our knowledge. Our approach can be readily adapted to other transition metal 𝐿 and rare earth 𝑀 absorption edges, and with a temporal resolution of <10ps, a wide range of ultrafast magnetization studies can be realized.
Published in: Optica, 10.1364/optica.480221, Optical Society of America