Enabling large tunnel magnetoresistance at room temperature in scalable epitaxial van der Waals magnet heterostructures

在可扩展外延范德华磁体异质结构中实现室温下的大隧道磁阻

• 批准号: 533948427
• 负责人: Dr. Joao Marcelo Jordao Lopes
• 金额: --
• 依托单位: Paul-Drude-Institut für Festkörperelektronik (PDI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/533948427?language=en
• 关键词: Enabling; large; tunnel; magnetoresistance; room

The emergence of atomically thin two-dimensional (2D) materials and their van der Waals (vdW) heterostructures has sparked new scientific interest, offering unprecedented electronic properties for next-generation technologies. 2D magnets, the latest addition to the 2D family, have unique characteristics that make them ideal for vdW heterostructure designs. 2D magnets have the potential to revolutionise magnetic sensors and spintronic technologies, particularly tunnel magnetoresistance (TMR) devices. These devices offer ultra-high sensitivity in magnetic field detection at room temperature, making them invaluable for applications such as magnetic sensors, data storage, memory, and computing. However, reliable and tunable TMR devices pose challenges with conventional materials. Recent advancements have achieved large TMR values using 2D magnets, however most of the reports are limited to cryogenic temperatures and studies are limited to exfoliated flakes. Scalable growth of 2D magnets and the fabrication of magnetic tunnel junctions (MTJs) with multiple layers separated by a tunnel barrier remain challenging and coherent spinpolarised electron tunneling across vdW tunnel barriers on TMR effects is also unexplored. The MagicTune project aims to address these challenges by controlling spin-polarised tunneling in 2D MTJs through twist angle and gate voltage control, achieving large and tunable TMR at room temperature. Scalable growth processes for high-quality vdW magnetic heterostructures with high Curie temperatures (TC) and perpendicular magnetic anisotropy (PMA) will be developed. The project will maximise tunnel spin polarisation in MTJs by exploiting momentum-conserving electron tunneling across vdW barriers. Robust room temperature TMR device operation with TMR ratios above 100% will be demonstrated using epitaxial vdW magnetic heterostructures. We have the following ambitious objectives: Objective 1. Develop scalable growth of high-quality 2D magnetic heterostructures with TC >= 350 K and PMA by molecular beam epitaxy. Objective 2. Tune and maximize the tunnel spin polarization in MTJs by twist angle, bias and gate control by exploiting momentum-conserving electron tunneling across 2D tunnel barriers. Objective 3. Demonstrate robust room temperature TMR device operation with TMR ratio >100% using scalable epitaxial vdW magnetic heterostructures. MagicTune will leverage expertise in epitaxial growth and characterization, synthesis of epitaxial graphene templates, tunnel magnetoresistance devices, twistronics, quantum and spin transport measurements, and nanofabrication of all-2D nanodevices. Success in MagicTune will drive breakthroughs in TMR device functionalities and enable high performance, compact, and energy-efficient technologies using 2D heterostructures. This project holds great promise at the forefront of multidisciplinary nanoscience and nanotechnology.

原子级薄的二维（2D）材料及其货车德瓦尔斯（vdW）异质结构的出现引发了新的科学兴趣，为下一代技术提供了前所未有的电子特性。2D磁体是2D系列的最新成员，具有独特的特性，使其成为vdW异质结构设计的理想选择。2D磁体有可能彻底改变磁传感器和自旋电子技术，特别是隧道磁阻（TMR）器件。这些器件在室温下的磁场检测中具有超高灵敏度，使其在磁传感器、数据存储、存储器和计算等应用中具有不可估量的价值。然而，可靠且可调谐的TMR器件对传统材料提出了挑战。最近的进展使用2D磁体实现了大的TMR值，但大多数报告仅限于低温温度，研究仅限于剥落的薄片。2D磁体的可扩展生长和具有由隧道势垒分离的多个层的磁性隧道结（MTJ）的制造仍然具有挑战性，并且跨vdW隧道势垒的相干自旋极化电子隧穿对TMR效应的影响也未被探索。MagicTune项目旨在通过扭转角和栅极电压控制来控制2D MTJ中的自旋极化隧穿，从而在室温下实现大的可调谐TMR，从而解决这些挑战。可扩展的生长工艺，高品质的vdW磁性异质结构具有高居里温度（TC）和垂直磁各向异性（PMA）将被开发。该项目将最大限度地利用跨VDW势垒的动量守恒电子隧穿在MTJ的隧道自旋极化。鲁棒的室温TMR器件的操作与TMR率超过100%将使用外延VDW磁性异质结构证明。我们有以下雄心勃勃的目标：目标1。开发通过分子束外延可扩展生长TC >= 350 K和PMA的高质量2D磁性异质结构。目标2.通过扭转角、偏置和栅极控制，利用跨2D隧道势垒的动量守恒电子隧穿，调整并最大化MTJ中的隧道自旋极化。目标3.使用可扩展的外延vdW磁性异质结构，演示TMR比率>100%的稳健室温TMR器件操作。MagicTune将利用外延生长和表征，外延石墨烯模板合成，隧道磁阻器件，双电子学，量子和自旋输运测量以及全二维纳米器件的纳米加工方面的专业知识。MagicTune的成功将推动TMR器件功能的突破，并实现使用2D异质结构的高性能，紧凑和节能技术。该项目在多学科纳米科学和纳米技术的前沿拥有巨大的希望。