Nonlinear suppression of dispersion broadening of ultrashort spin-wave pulses in thin yttrium iron garnet films

We study experimentally the nonlinear propagation of short pulses of forward volume spin waves in out-of-plane magnetized nanometer-thick yttrium iron garnet (YIG) films. We show that nonlinearity of the spin system can efficiently counteract dispersion broadening of the pulses, leading to the formation of envelope solitons. We demonstrate that in microscopic YIG systems, microwave powers of the order of 1 mW are sufficient to reach the soliton formation threshold. At powers slightly above this threshold, we achieve transmission of 3-ns spin-wave pulses over distances of up to 50 µm without increase in their temporal width. Our results demonstrate a promising way towards high-rate transmission of information in microscopic spin-wave circuits unaffected by detrimental dispersion effects.