Enhancement of Thermally Injected Spin Current through an Antiferromagnetic Insulator

We report a large enhancement of thermally injected spin current in normal metal (NM)/antiferromagnet (AF)/yttrium iron garnet (YIG), where a thin AF insulating layer of NiO or CoO can enhance the spin current from YIG to a NM by up to a factor of 10. The spin current enhancement in NM/AF/YIG, with a pronounced maximum near the Neel temperature of the thin AF layer, has been found to scale linearly with the spin-mixing conductance at the NM/YIG interface for NM = 3d, 4d, and 5d metals. Calculations of spin current enhancement and spin mixing conductance are qualitatively consistent with the experimental results.This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Science, under Award Grant No. DE-SC0009390. W. L. was supported in part by C-SPIN, one of six centers of STARnet, a SRC program sponsored by MARCO and DARPA. K. C. and S. Z. were supported by National Science Foundation under Grant No. ECCS-1404542. W. L. thanks Ssu-Yen Huang from National Taiwan University for fruitful discussions.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu