Giant tunnel magnetoresistance in two-dimensional van der Waals magnetic tunnel junctions: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Ag</mml:mi><mml:mtext>/</mml:mtext><mml:mi>Cr</mml:mi><mml:msub><mml:mi mathvariant="normal">I</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mtext>/</mml:mtext><mml:mi>Mo</mml:mi><mml:msub><mml:mi>Si</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">N</mml:mi><mml:mn>4</mml:mn></mml:msub><mml:mtext>/</mml:mtext><mml:mi>Cr</mml:mi><mml:msub><mml:mi mathvariant="normal">I</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mtext>/</mml:mtext><mml:mi>Ag</mml:mi></mml:mrow></mml:math>
Hao Liu, Pan Wang, Yixin Zong, Hongyu Wen, Yue‐Yang Liu, Jian‐Bai Xia
Abstract
With intrinsic magnetism, two-dimensional (2D) $\mathrm{Cr}{\mathrm{I}}_{3}$ has attracted tremendous interest because of the potential application in magnetic devices of smaller size. We propose to use 2D $\mathrm{Mo}{\mathrm{Si}}_{2}{\mathrm{N}}_{4}$ material, which has remarkable stability, excellent electronic properties, and high mobility, as tunnel barrier in vertical magnetic tunnel junction (MTJ), and demonstrate that it is able to generate a giant tunnel magnetoresistance (TMR) over ${10}^{5}%$ when integrated with $\mathrm{Cr}{\mathrm{I}}_{3}$ ferromagnetic layers and Ag electrodes. Combining with density-functional theory and nonequilibrium Green's function approach, we systematically investigate the electron transmission, band structures, and projected local density of states and elaborate the transmission mechanism. The TMR and spin injection efficiency maintain high values below 0.25 V. These results indicate that $\mathrm{Mo}{\mathrm{Si}}_{2}{\mathrm{N}}_{4}$ is a promising barrier material in future 2D vertical MTJs and provide important guidance for designing devices.