Spin-orbitronic devices based on 2D Rashba Janus crystals as active materials

Janus晶体是一种新的原子薄材料，具有两种不同的相和不同的原子排列方式。Janus晶体以双面罗马神的名字命名，一面面向未来，一面面向过去。从理论上讲，这些材料具有非凡的自旋电子特性，可以设计和制造基于自旋的电子设备，而不是目前计算机中发现的传统基于电荷的晶体管。到目前为止，由于样品制备的限制，器件制造一直受到限制。该项目旨在了解Janus层的自旋电子特性，并将其集成到基于自旋的场效应晶体管和门控器件中，用于下一代电子应用。社会影响将通过引入新一代自旋电子设备和降低高速电子设备的能耗来体现。该项目计划将高中、本科、硕士学生整合到一个活跃的研究环境中，以培养下一代工程师和科学家。通过活跃的实验室环境和实验室参观研究，将为代表性不足的社区提供就业机会。外展活动包括通过亚利桑那州立大学的SCENE项目让K-12学生参与进来。本项目重点研究二维（2D） Janus过渡金属二硫化物材料的器件物理，通过外部门控均衡Rashba和Dresselhaus效应，展示高性能自旋场效应管、可调谐自旋织构器件、弹道自旋输运场效应管。最初的实验将包括合成MoSSe、WSSe、WSTe和其他具有可调谐Janus场的外延和激子级2D Janus层，然后通过使用各种金属的欧姆接触来理解2D Janus半导体上的肖特基结。此外，高性能的自旋场效应晶体管器件将被制造与通道工程绝缘和优化栅极堆。材料将被表征，器件将优化工艺-结构-性能关系，以实现最高的自旋场效应管性能。工作重点是建立自旋进动和自旋输运、栅极可调自旋织构和二维Janus Rashba层上的自旋场效应晶体管操作的基础。该项目将寻求通过Dresselhaus-Rashba交叉现象抑制自旋弛豫来实现弹道自旋输运和自旋纹理操纵的方法。该项目的成功完成将建立二维Janus层的基本器件物理，展示基于这些二维Rashba Janus层的自旋场效应管，并通过Rashba- dresselhaus项之间的相互作用为高温抗散射自旋场效应管的运行奠定基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Named after the two-faced Roman god one looking to the future while the other facing to the past, Janus crystals are new atomically thin materials having two different phases with different atomic arrangements. Theoretically these materials have extraordinary spintronic properties, to design and fabricate spin-based electronic devices instead of traditional charge-based transistors found in current computers. So far device fabrication has been restrictive due to limitations in sample preparation. This project aims to understand the spintronic properties of Janus layers and to integrate them into spin-based field-effect transistors and gating devices for next-generation electronic applications. The societal impacts will manifest through the introduction of a new generation of spintronic devices and lowering energy consumption in high-speed electronic devices. The project plans to integrate high school, undergraduate, and master’s students into an active research environment to create next-generation engineers and scientists. Career opportunities will be offered to underrepresented communities through research in an active laboratory environment and laboratory tours. Outreach activities include, involvement of K-12 students through ASU’s SCENE program.This project focuses on studying the device physics of two-dimensional (2D) Janus transition metal dichalcogenide materials to demonstrate high-performance spin-FETs, tunable spin-texture devices, ballistic spin transport FETs by equalizing the Rashba and Dresselhaus effects by external gating. The initial experiments will involve synthesis of epitaxial and excitonic grade 2D Janus layers of MoSSe, WSSe, WSTe, and others with tunable Janus fields, followed by an understanding of Schottky junctions on 2D Janus semiconductors by using ohmic contact of a variety of metals. In addition, high-performance spin-FET devices will be fabricated with channel engineering insulation and optimized gate-stacks. Materials will be characterized, and devices will be optimized for process-structure-performance relations to achieve the highest spin-FET performance. Efforts will focus on establishing the foundations for spin precession and spin transport, gate-tunable spin textures, and spin FET operation on 2D Janus Rashba layers. The project will seek ways to achieve ballistic spin-transport and manipulation of spin-texture by suppressing spin relaxation through the Dresselhaus-Rashba crossover phenomena. The successful completion of this project will establish the fundamental device physics of 2D Janus layers, demonstrate spin-FETs based on these 2D Rashba Janus layers, and estswblish the basis for high-temperature scattering-resistant spin-FET operation through an interplay between Rashba-Dresselhaus terms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.