University of Vienna Extends Magnon Lifetime Nearly 100-Fold

A team led by Andrii Chumak at the University of Vienna, with collaborators at the University of Colorado Colorado Springs and institutions in Germany and Ukraine, measures magnon lifetimes of up to 18 microseconds — almost 100 times longer than previously observed — by exciting short-wavelength magnons (quantized spin waves) that are inherently insensitive to surface defects in ultra-pure yttrium iron garnet spheres cooled to 30 millikelvin. The team's key finding is that magnon lifetime is limited by material purity rather than fundamental physics, meaning further gains depend on materials engineering rather than new theory. Longer-lived magnons could serve as robust quantum memories and communication links between superconducting qubits, potentially enabling quantum computing hardware the size of a coin.