Wavenumber-dependent magnetic losses in YIG-GGG heterostructures at millikelvin temperatures
arXiv:2411.13414 · doi:10.1103/PhysRevB.111.134428
Abstract
Magnons have inspired potential applications in modern quantum technologies and hybrid quantum systems due to their intrinsic nonlinearity, nanoscale scalability, and a unique set of experimentally accessible parameters for manipulating their dispersion. Such magnon-based quantum technologies demand long decoherence times, millikelvin temperatures, and minimal dissipation. Due to its low magnetic damping, the ferrimagnet yttrium iron garnet (YIG), grown on gadolinium gallium garnet (GGG), is the most promising material for this objective. To comprehend the magnetic losses of propagating magnons in such YIG-GGG heterostructures at cryogenic temperatures, we investigate magnon transport in a micrometer-thick YIG sample via propagating spin-wave spectroscopy (PSWS) measurements for temperatures between 4K to 26mK. We demonstrate an increase in the dissipation rate with wavenumber at cryogenic temperatures, caused by dipolar coupling to the partially magnetized GGG substrate. Additionally, we observe a temperature-dependent decrease in spin-wave transmission, attributed to rare earth ion relaxations. The critical role of the additional dissipation channels at cryogenic temperatures is underpinned by the comparison of the experimental results with theoretical calculations and micromagnetic simulations. Our findings strengthen the understanding of magnon losses at millikelvin temperatures, which is essential for the future detection of individual propagating magnons.
9 pages, 4 figures
References in corpus (12)
- Hybridizing ferromagnetic magnons and microwave photons in the quantum limit
- Quantum technologies with hybrid systems
- Hybrid quantum systems based on magnonics
- Roadmap on Spin-Wave Computing
- An Introduction to Spin Wave Computing
- Hybrid magnonics: physics, circuits and applications for coherent information processing
- Exchange Magnon-Polaritons in Microwave Cavities
- Roadmap for Unconventional Computing with Nanotechnology
- Strong magnon-photon coupling with chip-integrated YIG in the zero-temperature limit
- Magnetic anisotropy and GGG substrate stray field in YIG films down to millikelvin temperatures
- Updating the phase diagram of the archetypal frustrated magnet Gd3Ga5O12
- Propagating spin-wave spectroscopy in nanometer-thick YIG films at millikelvin temperatures