Illustration of switching in CuMnAs. In the picture a hypothetical scenario is shown in which the magnetic field would generated by an electromagnetic coil. Because the coil on the two sublattices are winded in opposite directions they generate opposite magnetic fields. This is of course not possible in practice, instead in the experiment such magnetic fields are generated internally due to electrical current.
Electrical switching of an antiferromagnet
Abstract
Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net magnetization. However, relativistic quantum mechanics allows for generating current-induced internal fields whose sign alternates with the periodicity of the antiferromagnetic lattice. Using these fields, which couple strongly to the antiferromagnetic order, we demonstrate room-temperature electrical switching between stable configurations in antiferromagnetic CuMnAs thin-film devices by applied current with magnitudes of order 10^6 ampere per square centimeter. Electrical writing is combined in our solid-state memory with electrical readout and the stored magnetic state is insensitive to and produces no external magnetic field perturbations, which illustrates the unique merits of antiferromagnets for spintronics