Ultrafast and magnetoelectric phase transitions in antiferromagnets

Antiferromagnetic (AFM) NiO and RMnO3 (R=YbR=Yb, Ho) are a source of unusual types of magnetic phase control. In NiO an ultrafast reorientation of the antiferromagnetic order parameter is triggered by irradiation with a 100 fs light pulse which modifies the magnetic anisotropy. In YbMnO3 and HoMnO3, a magnetic or electric field induces ferromagnetic rare-earth ordering because of the magnetoelectric (ME) effect.