Van der Waals Antiferroelectric Magnetic Tunnel Junction: A First-Principles Study of a CrSe₂/CuInP₂S₆/CrSe₂ Junction

Abstract

Magnetic tunnel junctions (MTJs), ferroelectric/antiferroelectric tunnel junctions (FTJs/AFTJs), and multiferroic tunnel junctions (MFTJs) have recently attracted significant interest for technological applications of nanoscale memory devices. Until now, most of them are based on perovskite oxide heterostructures with a relatively high resistance-area (RA) product and low resistance difference unfavorable for practical applications. The recent discovery of the two-dimensional (2D) van der Waals (vdW) ferroelectric (FE) and magnetic materials has opened a new route to realize tunnel junctions with high performance and atomic-scale dimensions. Here, using first-principles calculations, we propose a new type of 2D tunnel junction: an antiferroelectric magnetic tunnel junction (AFMTJ), which inherits the features of both MTJ and AFTJ. This AFMTJ is composed of monolayer CuInP2S6 (CIPS) sandwiched between 2D magnetic electrodes of CrSe2. The AFTJ with nonmagnetic electrodes of TiSe2 on both sides of CIPS and the asymmetric AFTJ with both CrSe2 and TiSe2 electrodes are also investigated. Based on quantum-mechanical modeling of the electronic transport, sizeable tunneling electroresistance effects and multiple nonvolatile resistance states are demonstrated. More importantly, a remarkably low RA product (less than 0.1 Ω·μm2) makes the proposed vdW AFMTJs superior to the conventional MFTJs in terms of their promising nonvolatile memory applications. Our calculations provide new guidance for the experiment and application of nanoscale memory devices.

LaOMS2 (M = Ti, V, and Cr): novel crystal spin valves without contact

“…To control the magnetic alignment, heterostructures have been commonly used, such as memory devices and tunnel junctions. 12 To demonstrate the concept, we used LaOCrS 2 as an example. To match the lattice in the junction, 2D materials inevitably experience strain, which may affect their electronic properties.…”

“…[4][5][6] For example, graphene was used in integrated circuits. 7 Transition metal dichalcogenides (TMDs), [8][9][10] (functionalized) MXenes, 11 CuInP 2 S 6 , 12,13 and Bi 2 O 2 Se 14 have been investigated for field-effect transistors or spintronics. However, the traditional devices and ICs are no longer enough for the needs of modern circuits.…”

Tunnel electroresistance effect in a two-dimensional organic ferroelectric tunnel junction

“…9,10 Since 2D materials are only a few atomic layers thick, FTJs based on 2D ferroelectric materials greatly reduce the size of the device, thus attracting more attention. 11–13…”

“…9,10 Since 2D materials are only a few atomic layers thick, FTJs based on 2D ferroelectric materials greatly reduce the size of the device, thus attracting more attention. [11][12][13] At present, a large number of 2D ferroelectric materials with in-plane polarization or out-of-plane polarization are successfully predicted by theoretical work, such as the group IV chalcogenides (SnS, GeSe), 14 the group V phosphorene-like structure compounds or monolayers (BiP, SbN), 15,16 In 2 Se 3 , 17 CuInP 2 S 6 18 and so on. Moreover, SnTe, In 2 Se 3 and CuInP 2 S 6 have also been prepared experimentally.…”

A van der Waals Ferroelectric Tunnel Junction for Ultrahigh‐Temperature Operation Memory

“…[6,[10][11][12] The Joule heating of some memory devices mainly originates from the core active component such as ferroelectric tunnel junctions (FTJs), which use a thin ferroelectric layer to switch between two or more conductance states by modify the tunnel barrier. [7,[13][14][15][16][17] However, high temperature aroused from Joule heat or harsh environment could severely compromise the performance of ferroelectric layers. [4,[18][19][20] The high-temperature situations, whether it is originated from the internal Joule heating or the external harsh surroundings, determine that the future FTJs need satisfy high-temperature operation.…”