Enhanced Longitudinal Relaxation of Magnetic Solitons in Ultrathin Films

Abstract

The authors present a phenomenological model of the $l\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}d\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}l$ relaxation processes of magnetic domain walls in ferromagnetic films featuring the Dzyaloshinskii-Moriya interaction. This model enables predictions in quantitative agreement with experiments. In contrast to expectations from state-of-the-art theories, for ultrathin films the contribution from longitudinal relaxation is comparable to or even $s\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}r$ $t\phantom{\rule{0}{0ex}}h\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n$ $a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}y$ $o\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}h\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}r$ $m\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}h\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}m$, including spin pumping. This effect is generic and valid for any noncollinear texture, including the domain walls and skyrmions that are technologically relevant for logic and memory devices.