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Raí Menezes (UFPE) – Magnonics in 2D magnetic materials – 12 de Agosto 14:00
12 de agosto:14:00 - 15:00
Two-dimensional (2D) magnetic materials, such as monolayer chromium trihalides and manganese dichalcogenides, have recently drawn immense attention to both theoretical and experimental research due to their fundamental significance and promising technological applications. The manipulation of magnetic textures, such as domain-walls, spin-waves (SW), and magnetic skyrmions in ultrathin materials opens a field of possibilities for new device concepts. Particularly, 2D magnetic materials are readily established as a promising platform for high-frequency magnonics. However, the manipulation of SWs in such systems remains mostly unexplored. In this talk, we will discuss the SW properties in monolayer chromium trihalides CrBr3 and CrI3. Using magnetic parameters obtained from first-principle calculations, we perform spin-dynamics simulations of the SW propagation in the 2D material. We reveal that their spin-wave dispersion can be tuned in a broad range of frequencies by strain, paving the way towards flexo-magnonic applications. We further show that ever-present halide vacancies in these monolayers host sufficiently strong Dzyaloshinskii–Moriya interaction to scatter spin-waves, which can be turned useful in the design of spin-wave guides by defect engineering. Finally we discuss the spectra of spin-waves propagating across a Moiré-periodic modulation of magnetic parameters in a van der Waals heterobilayer, and show that the several nanometer small Moiré periodicities in such samples are ideal for the realization of a magnonic crystal in the terahertz frequency range. Recalling the broad degree of manipulations available in 2D materials, we conclude that these systems are a front-runner for prospective terahertz magnonic applications.