Press release: Giant magnetic response of a two-dimensional antiferromagnet

The key to new functionality beyond electronics lies in control of electron spins. Although ferromagnets are used in many existing magnetic devices, antiferromagnets are expected to provide larger capacity, higher information security, and higher-speed switching than ferromagnets do. However, the response of an antiferromagnet to a uniform magnetic field is usually so small that a huge magnetic field is needed for control of spins, which practically makes antiferromagnets less useful than ferromagnets. This long-standing problem was solved by Dr. Hidemaro Suwa at the University of Tokyo in collaboration with researchers at the University of Tennessee, Brookhaven National Laboratory, Argonne National Laboratory, and Charles University. The researchers demonstrated giant antiferromagnetic responses to sub-tesla external fields by exploiting extremely strong two-dimensional critical fluctuations preserved under a symmetry-invariant exchange anisotropy, which was built into an artificially synthesized superlattice of SrIrO₃ and SrTiO₃. The unusual increase of the ordering temperature enables highly efficient control of the antiferromagnetic order. Their results demonstrate that symmetry can be exploited in spin-orbit-coupled magnets for developing high-performance antiferromagnetic devices.

Press release from School of Science, the University of Tokyo: http://www.s.u-tokyo.ac.jp/en/info/5924/

Published article: Lin Hao, D. Meyers, Hidemaro Suwa, Junyi Yang, Clayton Frederick, Tamene R. Dasa, Gilberto Fabbris, Lukas Horak, Dominik Kriegner, Yongseong Choi, Jong-Woo Kim, Daniel Haskel, Philip J. Ryan, Haixuan Xu, Cristian D. Batista, M. P. M. Dean, Jian Liu, Giant magnetic response of a two-dimensional antiferromagnet, Nature Physics, https://www.nature.com/articles/s41567-018-0152-6.