On-chip quantum MagNonIcs

Objectif

Quantum technologies allow to harness the fundamental properties of nature for practical applications. An ongoing challenge is the combination of these technologies, to convert between flying and stationary qubit systems, as for example quantum transducer promise. The emerging field of quantum magnonics, dealing with precessional excitations of electron spins at single-magnon power levels, offers the unique opportunity to integrate different quantum systems within a solid-state platform. Although quantum magnonics was theoretically formulated in the 1960’s, only now progress in cryogenics and ultra-sensitive microwave technology allows the first experimental steps. While recent miniaturisation of monocrystalline yttrium iron garnet (YIG) waveguides provides access to propagating single-mode magnons, their use in larger quantum circuits requires the development of different separate building blocks, such as phase shifters, delay lines and attenuators. The project On-chip quantum MagNonIcs (OMNI) is formulated to demonstrate these functionalities on a dynamic on-chip 3-terminal device (3-TD). To this end, I will use the unique magnonics knowledge at the University of Vienna and combine it with my strong expertise in quantum optics, quantum electronics and nanofabrication. The 3-TD YIG device will be designed and modelled numerically, fabricated using modern nanopatterning techniques, and characterized by Brillouin light scattering and microwave spectroscopy at ultra-low temperatures. The device operation will be governed by the magnon dispersion affecting its passage through a non-uniform magnetic field created by an electric current. The successful realization of the project will allow me to demonstrate the required building blocks of Quantum Magnonics and will establish me as a future research leader at the forefront of this novel field of research.