  In this work, we utilize voltage controlled magnetic anisotropy (VCMA) to
manipulate magnetic skyrmions that are fixed in space. Memory devices based on
this strategy can potentially be of smaller footprint and better energy
efficiency than current-controlled motion-based skyrmionic devices. To
demonstrate VCMA induced manipulation of skyrmions, we fabricate
antiferromagnet/ferromagnet/oxide heterostructure films where skyrmions can be
stabilized without any external magnetic field due to the presence of exchange
bias. These isolated skyrmions were annihilated by applying a voltage pulse
that increased PMA. On the other hand, decreasing PMA promoted formation of
more skyrmions. Furthermore, skyrmions can be created from chiral domains by
increasing PMA of the system. To corroborate our experimental observations, we
performed micromagnetic simulation. The proposed method could potentially lead
to novel skyrmion-based memory devices.
