Van der Waals Multiferroic Tunnel Junctions

Yurong Su; Xinlu Li; Meng Zhu; Jia Zhang; Long You; Evgeny Y Tsymbal

doi:10.1021/acs.nanolett.0c03452

Van der Waals Multiferroic Tunnel Junctions

Nano Lett. 2021 Jan 13;21(1):175-181. doi: 10.1021/acs.nanolett.0c03452. Epub 2020 Dec 2.

Authors

Yurong Su¹, Xinlu Li², Meng Zhu², Jia Zhang², Long You¹, Evgeny Y Tsymbal³

Affiliations

¹ School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074 Wuhan, China.
² School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China.
³ Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588, United States.

PMID: 33264014
DOI: 10.1021/acs.nanolett.0c03452

Abstract

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 Fe_nGeTe₂ (n = 3, 4, 5) electrodes and 2D ferroelectric In₂Se₃ barrier layers. We demonstrate that such Fe_mGeTe₂/In₂Se₃/Fe_nGeTe₂ (m, n = 3, 4, 5; m ≠ n) MFTJs exhibit multiple nonvolatile resistance states associated with different polarization orientation of the ferroelectric In₂Se₃ layer and magnetization alignment of the two ferromagnetic Fe_nGeTe₂ layers. We find a remarkably low RA product (less than 1 Ω·μm²) which makes the proposed vdW MFTJs superior to the conventional MFTJs in terms of their promise for nonvolatile memory applications.

Keywords: Multiferroic tunnel junctions; multiple nonvolatile resistance states; resistance-area product; tunneling electroresistance; tunneling magnetoresistance; van der Waals materials.