Xu Meng, Li Mingen, Khanal Pravin, Habiboglu Ali, Insana Blake, Xiong Yuzan, Peterson Thomas, Myers Jason C, Ortega Deborah, Qu Hongwei, Chien C L, Zhang Wei, Wang Jian-Ping, Wang W G
Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Phys Rev Lett. 2020 May 8;124(18):187701. doi: 10.1103/PhysRevLett.124.187701.
We demonstrate a voltage-controlled exchange bias effect in CoFeB/MgO/CoFeB magnetic tunnel junctions that is related to the interfacial Fe(Co)O_{x} formed between the CoFeB electrodes and the MgO barrier. The unique combination of interfacial antiferromagnetism, giant tunneling magnetoresistance, and sharp switching of the perpendicularly magnetized CoFeB allows sensitive detection of the exchange bias. We find that the exchange bias field can be isothermally controlled by magnetic fields at low temperatures. More importantly, the exchange bias can also be effectively manipulated by the electric field applied to the MgO barrier due to the voltage-controlled antiferromagnetic anisotropy in this system.
我们在CoFeB/MgO/CoFeB磁性隧道结中展示了一种电压控制的交换偏置效应，该效应与在CoFeB电极和MgO势垒之间形成的界面Fe(Co)Oₓ有关。界面反铁磁性、巨隧穿磁电阻以及垂直磁化的CoFeB的急剧切换的独特组合使得能够灵敏地检测交换偏置。我们发现，在低温下，交换偏置场可以通过磁场进行等温控制。更重要的是，由于该系统中电压控制的反铁磁各向异性，交换偏置也可以通过施加到MgO势垒的电场有效地进行调控。
