Physics ABC Seminar: by Dr. Vinayak Bhat, International Research Centre MagTop, Warsaw, Poland
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Speaker: Dr. Vinayak Bhat, International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland
Title: Direct Observation of Magnon Modes in Kagome Artificial Spin Ice with Topological Defects
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Meeting ID: 976 1386 7009
Kagome artificial spin ice (KASI) is a network of Ising type nanobars on a kagome lattice. We investigate spin dynamics of a KASI consisting of Ni81Fe19 nanomagnets arranged on an interconnected kagome lattice using broadband ferromagnetic resonance (FMR), magnetic force microscopy (MFM), micro-focus Brillouin light scattering (BLS) microscopy and X-ray photoemission electron microscopy (XPEEM). Micro-focus BLS performed on magnetically disordered states exhibit a series of magnon resonances which depend on topological defect configurations. We experimentally reconfigure microstates in ASI using a 2D vector field protocol and apply microwave-assisted switching to intentionally trigger reversal. Our work is key for the creation of avalanches inside the kagome ASI and reprogrammable magnonics based on ASIs.
Acknowledgement: The research was supported by the Swiss National Science Foundation via Grant No. 163016. V.S. Bhat acknowledges support from the foundation for Polish Science through the IRA Programme financed by EU within SG OP Programme.