1 research outputs found
Temperature dependent relaxation of dipole-exchange magnons in yttrium iron garnet films
Low energy consumption enabled by charge-free information transport, which is
free from ohmic heating, and the ability to process phase-encoded data by
nanometer-sized interference devices at GHz and THz frequencies are just a few
benefits of spin-wave-based technologies. Moreover, when approaching cryogenic
temperatures, quantum phenomena in spin-wave systems pave the path towards
quantum information processing. In view of these applications, the lifetime of
magnonsspin-wave quantais of high relevance for the fields of magnonics,
magnon spintronics and quantum computing. Here, the relaxation behavior of
parametrically excited magnons having wavenumbers from zero up to was experimentally investigated in the temperature range
from 20 K to 340 K in single crystal yttrium iron garnet (YIG) films
epitaxially grown on gallium gadolinium garnet (GGG) substrates as well as in a
bulk YIG crystalthe magnonic materials featuring the lowest magnetic damping
known so far. As opposed to the bulk YIG crystal in YIG films we have found a
significant increase in the magnon relaxation rate below 150 Kup to 10.5
times the reference value at 340 Kin the entire range of probed wavenumbers.
This increase is associated with rare-earth impurities contaminating the YIG
samples with a slight contribution caused by coupling of spin waves to the spin
system of the paramagnetic GGG substrate at the lowest temperatures