Amplification of spin-transfer torque in magnetic tunnel junctions with an antiferromagnetic barrier
Amplification of spin-transfer torque in magnetic tunnel junctions with an antiferromagnetic barrier
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DOI：
10.1103/physrevb.99.104417
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发表时间：
2019-03-13
影响因子：
3.7
通讯作者：
Zhang, Shufeng
中科院分区：
文献类型：
--
作者：
Cheng, Yihong;Wang, Weigang;Zhang, Shufeng
从理论上研究了以反铁磁绝缘体（AFI）作为隧道势垒的磁隧道结（MTJs）中的自旋传递力矩。当施加有限偏置电压到MTJ时，隧道电子的能量松弛导致两个金属层的不对称加热。因此，将有一个磁振子电流流过AFI层，除了电子自旋传递扭矩外，还产生一个磁振子传递扭矩。与具有非磁性绝缘体的磁振子传输相比，我们发现具有AFI势垒的磁振子传递力矩可以比隧道电子的传统自旋传递力矩大几倍。本研究提出了一种实现mtj中更有效切换的潜在方法，并为基于afi的mtj的实验研究提供了动力。
We theoretically study spin-transfer torques in magnetic tunnel junctions (MTJs) with an antiferromagnetic insulator (AFI) as the tunnel barrier. When a finite voltage bias is applied to the MTJ, the energy relaxation of the tunnel electrons leads to asymmetric heating of two metallic layers. Consequently, there would be a magnon current flowing across the AFI layer, resulting a magnon transfer torque in addition to the electron spin-transfer torque. Comparing to MTJs with a nonmagnetic insulator which prohibits the magnon transmission, we find the magnon transfer torque with an AFI barrier could be several times larger than the conventional spin-transfer torque of the tunnel electrons. This study presents a potential method to realize more efficient switching in MTJs and provides a motivation of experimental search for AFI-based MTJs.