Imaging Nano- and Micrometer-sized Magnetic Insulator Devices in the Presence of Spin-Torque
The spin Hall effect produces significant spin-torque from a charge current to enable reversible switching of conducting magnets. We study electrically insulating magnets, where the low intrinsic magnetic damping and the elimination of shunting currents through the magnet are expected to significantly reduce the critical current required for switching. With nano- and micrometer sized devices of Lu3Fe5O12 (LuIG) in conjunction with the spin Hall metal Tantalum, we directly image the magnetic state before and after a current pulse using scanning SQUID microscopy. We present preliminary results that show that the switching symmetry observed to date is opposite that expected from the spin Hall effect, and instead follows the Oersted-field assisted by Joule heating. Successful manipulation of magnetic insulators by electrical currents can be a platform for spintronic devices, and would be an ideal material to couple to other sources of large spin torque such as topological insulators, which have recently been shown to have the largest spin Hall effects to date.
Sunday, Sept. 20, 2015, 8 a.m. — Tuesday, Sept. 22, 2015, 10 p.m. CT
Austin, TX, United States
Technical conference and networking event for SRC members and students.