The ideal substrate for yttrium iron garnet films in quantum magnonics
Rostyslav O. Serha·Andrii V. Chumak·Philipp Pirro·Michal Urbánek·Carsten Dubs·Christo Guguschev·Bernd Aichner·David Schmoll·Julien Schäfer·J. Panda·Matthias Weiler
Abstract Quantum magnonics leverages the quantum properties of magnons to advance nanoscale quantum information technologies. Ferrimagnetic yttrium iron garnet (YIG), valued for its exceptionally low magnetic damping, is typically grown as thin films on gadolinium gallium garnet (GGG) for lattice matching. However, paramagnetic GGG introduces additional damping at low temperatures due to substrate magnetization, limiting quantum applications. Here, we study magnetic damping in a 150 nm-thick YIG