Atomic magnetism of skyrmion lattices: Probing Dzyaloshinskii-Moriya interactions using advanced low temperature conversion electron Mössbauer spectroscopy

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My research program is focused on the study of the mechanisms responsible for nanoscale magnetism, especially at interfaces. Of special interest is understanding the stabilization of the nanosized swirls of magnetic texture called skyrmions. Skyrmions behave as particles and can be moved, created and annihilated. They will revolutionize spintronics as they can be made to perform arithmetic logic, and offer ultra low energy information storage and radio frequency technologies at room temperature using electrical currents. Creating and controlling skyrmions requires knowing how to manipulate the spin-orbit coupling (SOC) magnetism of neighbouring atoms at interfaces. Spectroscopy is a natural tool to use to quantify SOC, and Mössbauer spectroscopy is ideally suited to probe the SOC and interfacial magnetism. The chirality of skyrmions determines most properties, and the chiral interactions are stabilized by the Dzyaloshinskii-Moriya interaction (DMI). In the 1960s and 70s, Mössbauer spectroscopy was key to quantifying DMI in bulk compounds, and identifying the underlying physics of DMI-driven magnetism that are now used in skyrmionic thin films. With the proposed equipment and my expertise in spectroscopy and new detector physics, I intend to open up a new avenue towards understanding the interface physics of skyrmions.******This equipment proposal is for a Mössbauer refrigeration system with 5 to 300 K (-270 to 25C) temperature capability. It will provide a vibration-free and temperature controlled environment for novel conversion electron Mössbauer spectroscopy experiments on skymionic (and other) thin films. The challenges of updating this technique to thin films are significant, but my group is optimally positioned to succeed. The experiments using the proposed equipment will provide key information and complement the other techniques my group uses, such as x-ray synchrotron spectroscopies that also probe SOC magnetism. Overall, the new insights my HQP discover are sure to enhance significantly the understanding of SOC, and the identification of the physics of processes at interfaces from SOC effects, anisotropy, and DMI. This new knowledge will apply well beyond skyrmionic films to the magnetism at interfaces that underlie current and future information storage (e.g. media and sensing). Knowledge translation with industrial collaborators at Seagate Technology R&D will feed into new technologies. Spectroscopy is central to my research and HQP training, and the requested equipment will advance both. The research we do with this equipment will have my HQP learn cutting-edge instrument design and construction (including new 3D printing and design skills that are transferable to advanced manufacturing), vacuum systems, cryogenics, detectors, fast electronics and computer data acquisition. The skills my HQP learn with this equipment will serve them exceptionally well later in their careers in research- and technology-based industries.