Direct imaging of thermally driven domain wall motion in magnetic insulators.

TitleDirect imaging of thermally driven domain wall motion in magnetic insulators.
Publication TypeJournal Article
Year of Publication2013
AuthorsJiang W, Upadhyaya P, Fan Y, Zhao J, Wang M, Chang L-T, Lang M, Wong KL, Lewis M, Lin Y-T, Tang J, Cherepov S, Zhou X, Tserkovnyak Y, Schwartz RN, Wang KL
JournalPhysical review letters
Date Published2013 Apr 26

Thermally induced domain wall motion in a magnetic insulator was observed using spatiotemporally resolved polar magneto-optical Kerr effect microscopy. The following results were found: (i) the domain wall moves towards hot regime; (ii) a threshold temperature gradient (5  K/mm), i.e., a minimal temperature gradient required to induce domain wall motion; (iii) a finite domain wall velocity outside of the region with a temperature gradient, slowly decreasing as a function of distance, which is interpreted to result from the penetration of a magnonic current into the constant temperature region; and (iv) a linear dependence of the average domain wall velocity on temperature gradient, beyond a threshold thermal bias. Our observations can be qualitatively explained using a magnonic spin transfer torque mechanism, which suggests the utility of magnonic spin transfer torque for controlling magnetization dynamics.

Alternate JournalPhys. Rev. Lett.