Formation, propagation, reflection, and collision of microwave envelope solitons in yttrium iron garnet films

Abstract

The end edge reflection and collision of backward volume wave bright microwave magnetic envelope solitons in long and narrow yttrium iron garnet single-crystal films has been studied experimentally. The experiments were done on 5.1-m-thick, 1-mm-wide films. The bright solitons were excited by single or double 8-36-ns-wide microwave pulses with a nominal carrier frequency of 5.8 GHz. The experiments utilized a movable transducer structure to make measurements for a range of transducer separations from 2 to 15 mm and for pulses before and after reflection. The soliton character was established from single-pulse decay versus time and distance measurements. Three decay regions were observed, a slow decay region before soliton formation, a fast decay region characteristic of solitons, and a second slow decay for linear pulses. The soliton region included both incident and reflected pulses. The exponential decay rate for the soliton regime was greater than for the linear. The soliton pulses retained the same shape and speed after edge reflection. An observed drop in pulse amplitude after passing under the pickup transducer provided a way to measure the actual power and amplitude of the soliton signal. The measured amplitudes and widths were in fair agreement with predictions for a simple sech-type order one soliton pulse. For properly timed double-pulse experiments in which a reflected lead pulse collides with the follow-on pulse before detection, the effects of soliton collisions could be examined. In the single soliton power regime, the pulses were found to retain their shape and speed after collision. At higher powers, shapes were not retained. In addition, a wake effect was observed in which the lead pulse causes a change in the detected signal for the follow-on pulse, even without collision.

Magnetic droplet solitons generated by pure spin currents

“…Dynamical magnetic envelope solitons, similar to the well-known temporal optical solitons [2], were observed about three decades ago in low-damping films of Yttrium Iron Garnet (YIG) [3,4], and have been intensively studied over the last years (see [5] and references therein). Because of the dynamic nature of these states, they are inhibited by the magnetic damping.…”

Self-Generation of Microwave Magnetic Envelope Soliton Trains in Yttrium Iron Garnet Thin Films

“…Most soliton experiments to date, however, have involved the application of input pulse signals and the observation of the soliton pulses which evolve as a result of these inputs. Many such experiments have been done for microwave magnetic envelope (MME) solitons in magnetic films of yttrium iron garnet (YIG) (see, e.g., [4][5][6][7][8][9][10][11] and literature therein). In all of these experiments, externally applied microwave pulses were used to produce the solitons.…”

Renormalized resonance frequencies of a ferrite sphere coupled to an LR circuit: Comparison of theory and experiment

“…Around the same time, it served as a convenient experimental system for the study of nonlinear processes and instabilities in magnetic systems (5). More recently, thin films of YIG have proved ideal for the generation and detailed study of envelope solitons (6).…”