Antiferromagnets are of potential use in the development of spintronic devices due to their ultrafast dynamics, insensitivity to external magnetic fields and absence of magnetic stray fields. Similar to their ferromagnetic counterparts, antiferromagnets can store information in the orientations of the collective magnetic order vector. However, the readout magnetoresistivity signals in simple antiferromagnetic films are weak, and reorientation of the magnetic order vector via optical excitation has not yet been achieved. Here we report the reversible and reproducible quenching of antiferromagnetic CuMnAs into nano-fragmented domain states using either electrical or ultrashort optical pulses. The changes in the resistivity of the system approach 20% at room temperature, which is comparable to the giant magnetoresistance ratios in ferromagnetic multilayers. We also obtain a signal readout by optical reflectivity.

反铁磁体具有超快的动力学特性，对外部磁场不敏感以及没有杂散磁场，因此在自旋电子器件的开发中具有潜在的用途。类似于其铁磁对应物，反铁磁体可以沿集体磁阶矢量的方向存储信息。然而，在简单的反铁磁膜中读出的磁电阻率信号很弱，并且尚未实现通过光激发对磁阶向量进行重新定向。在这里，我们报告使用电脉冲或超短光脉冲将可逆性和可再现性的反铁磁CuMnAs淬灭成纳米碎片畴态。在室温下，系统电阻率的变化接近20％，这可与铁磁多层膜中的巨磁阻比相媲美。我们还通过光反射率获得信号读数。