Su Yurong, Li Xinlu, Zhu Meng, Zhang Jia, You Long, Tsymbal Evgeny Y
School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074 Wuhan, China.
School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China.
Nano Lett. 2021 Jan 13;21(1):175-181. doi: 10.1021/acs.nanolett.0c03452. Epub 2020 Dec 2.
Multiferroic tunnel junctions (MFTJs) have aroused significant interest due to their functional properties useful for nonvolatile memory devices. So far, however, all of the existing MFTJs have been based on perovskite-oxide heterostructures limited by a relatively high resistance-area (RA) product unfavorable for practical applications. Here, using first-principles calculations, we explore spin-dependent transport properties of van der Waals (vdW) MFTJs which consist of two-dimensional (2D) ferromagnetic FeGeTe ( = 3, 4, 5) electrodes and 2D ferroelectric InSe barrier layers. We demonstrate that such FeGeTe/InSe/FeGeTe (, = 3, 4, 5; ≠ ) MFTJs exhibit multiple nonvolatile resistance states associated with different polarization orientation of the ferroelectric InSe layer and magnetization alignment of the two ferromagnetic FeGeTe layers. We find a remarkably low RA product (less than 1 Ω·μm) which makes the proposed vdW MFTJs superior to the conventional MFTJs in terms of their promise for nonvolatile memory applications.
多铁性隧道结（MFTJs）因其对非易失性存储器件有用的功能特性而引起了广泛关注。然而，到目前为止，所有现有的MFTJs都基于钙钛矿氧化物异质结构，受限于相对较高的电阻面积（RA）乘积，不利于实际应用。在此，我们使用第一性原理计算，探索由二维（2D）铁磁体FeGeTe（ = 3、4、5）电极和二维铁电体InSe势垒层组成的范德华（vdW）MFTJs的自旋相关输运特性。我们证明，这种FeGeTe/InSe/FeGeTe（， = 3、4、5； ≠ ）MFTJs表现出与铁电InSe层的不同极化取向以及两个铁磁FeGeTe层的磁化排列相关的多个非易失性电阻状态。我们发现了极低的RA乘积（小于1 Ω·μm），这使得所提出的vdW MFTJs在非易失性存储应用前景方面优于传统的MFTJs。
