Linear magnetoelectric memory and training effect in the honeycomb antiferromagnet Co₄Nb₂O₉

We report observation of ultrarobust linear magnetoelectric memory and significant training effect in a honeycomb antiferromagnet Co4Nb2O9 , which is controllable by magnetic and electric fields. The memory states show distinct linear magnetoelectric coefficients over a broad magnetic field range. Antiferromagnetic domain evolution is believed to be responsible for the versatile memory behaviors promisingly accessible in multiferroics and other magnetoelectric materials such as topological insulators. The compensated antiferromagnetic phase essential to the magnetoelectric memory may allow to further integrate the unique merits of antiferromagnetic spintronics such as ultrahigh density and ultrafast switching.