Surface acoustic waves for magnonic devices

A substantial portion of today's magnetism research community dedicates its efforts to achieving highly integrated, rapid, and energy-efficient information and communication technologies that can operate at room temperature. In this context, Spin Waves (SW) emerge as promising contenders. They represent collective excitations of electron spins within magnetic materials, traversing the spin lattice to convey information (see Fig.1). At INSP, our primary interest lies in instigating SWs within nanostructures through GHz dynamic strain, in the form of acoustic waves. Indeed, the advent of spintronic devices that manipulate magnetization through strain rather than conventional inductive methods (like antennas) holds the potential for substantial reductions in energy dissipation. In our pioneering approach, SWs find their ignition in the propagation of surface acoustic waves (SAWs), a well-established technology already employed in contemporary sensors, filters, and microwave circuitry. Recently, our research group demonstrated that SAWs, can effectively excite spin waves in Fe epitaxied on GaAs [1,2]. During this thesis, the final objective will be to control SW emission in different waveguides externally and independently by exciting the magnetic resonance of Fe pads, whilst keeping the waveguide insensitive to the magnetoelastic interaction, thanks to nitrogen implantation. The student's involvement will begin with device fabrication and the comprehensive examination of its magnetic characteristics. Subsequently, he/she student will delve into RF electrical and optical magnetoacoustics measurements to find the right coupling conditions. This multifaceted experience will encompass hands-on exposure to clean room protocols, optics, and RF electronics. Ultimately, the student will actively contribute to the development of a phenomenological model aimed at elucidating the observed phenomena. [1] Duquesne et al., Phys. Rev. Appl. 12, 024042 (2019) [2] Rovillain et al., Phys. Rev. Appl. 18, 064043 (2022) [3] Kuszewski et al., Phys. Rev. Appl. 10, 034036 (2018) [4] Kraimia et al., Phys. Rev. B 101, 144425 (2020). Techniques/methods in use: Clean room techniques, RF electronics, magnetoacoustics and TR-MOKE measurements techniques Applicant skills: Good background in magnetism, Taste for experimental physics.