Scalable Digital Spin Logic Devices

该项目将结合PI在自旋输运中的专业知识和Co-PI在多铁性材料和器件中的专业知识，开发一种新的逻辑范式，能够绕过基于电荷的电路的基本限制。该团队将在可扩展的架构中利用电子自旋和固态磁性之间的相互作用，从而避免与电子逻辑电路操作相关的缺点。非平衡自旋（从单畴铁磁比特注入非磁性、自旋守恒的通道材料）可以通过自旋扭矩和交换力与其他磁比特耦合。由多铁质和压电材料异质结构的界面磁致伸缩应变以几乎无耗散的方式诱导的有效场可以实现磁化开关和逻辑处理的驱动。这些材料、耦合和驱动的概念是指导研究任务的自然主题，并将导致实现能够满足可行计算系统的五个基本要求的技术：非线性、增益、可连接性、反馈消除和一整套布尔运算。所提出的研究的智力价值在于它直接解决了实现全自旋逻辑器件技术必须克服的基本科学挑战。将研究硅和锗作为半导体自旋守恒通道材料的模型。测量铁磁与通道材料界面处的自旋转矩和交换耦合强度。压电电压介导对磁开关势垒的控制将被实现，并且利用邻近非磁性通道材料中的非平衡自旋进行磁位的开关将首次被证明。结果将详细了解利用压控磁致伸缩产生的有效磁场在最小的非平衡自旋和最小的能量耗散的情况下实现快速磁化开关的必要条件。所提出的活动的更广泛影响在于，这种新的逻辑处理范式有可能在基于电荷的电子系统中延续性能趋势（通过数十年的扩展建立），并产生重大的经济、环境和社会影响。自旋电子学器件提供的低功耗、瞬时电子器件的优势增加了器件的可移植性，这在当今尤为重要。能源成本的增加和对环境的破坏。通过在科学和工程的各个方面培养研究生，包括半导体器件设计、加工、测量和自旋电子学，实现了更广泛的影响；以及旨在扩大中小学生、家长和公众对半导体电子行业规模的历史重要性的理解，以及未来十年规模将结束所面临的挑战的活动。

This project will combine expertise of PI in spin transport and of Co-PI in multiferroic materials & devices to develop a new logic paradigm capable of circumventing the fundamental limitations of charged-based circuits. The team will exploit the interactions between electron spin and solid-state magnetism in a scalable architecture which avoids the shortcomings relevant to electronic logic circuit operation. Non-equilibrium spin (injected into a nonmagnetic, spin-conserving channel material from single-domain ferromagnetic bits) can couple to other magnetic bits through spin torque and exchange force. The actuation of magnetization switching and therefore logic processing, is enabled by effective fields induced by interfacial magnetostrictive strain from multiferroic and piezoelectric material heterostructures in a virtually dissipation-free way. These concepts of materials, coupling, and actuation are natural themes which guide the research tasks and will lead toward realization of a technology capable of satisfying the five fundamental requirements for viable computing systems: non-linearity, gain, concatenability, feedback elimination, and a complete set of Boolean operations. The Intellectual Merit of the proposed research is that it directly addresses the fundamental scientific challenges that must be overcome to realize an all-spin logic device technology. Silicon and germanium will be studied as model semiconductor spin-conserving channel materials. The spin torque and exchange coupling strengths at the interface between ferromagnet and channel material will be measured. Piezoelectric voltage-mediated control over magnetic switching barriers will be achieved, and switching of a magnetic bit using non-equilibrium spins in a neighboring non-magnetic channel material will be demonstrated for the first time. The result will be a detailed understanding of the necessary conditions for using the effective magnetic field generated by voltage-controlled magnetostriction to effect rapid magnetization switching with minimal forcing by non-equilibrium spins and minimal energy dissipation. The Broader Impact of the proposed activity is in the potential of this new logic processing paradigm to continue performance trends (established through decades of scaling) in charge-based electronic systems with significant economic, environmental, and societal ramifications. The advantages afforded by spintronics devices of enabling lower-power, instant-on electronics allow increased device portability and are especially important in light of today?s increasing energy costs and its environmental damage. Additional Broader Impact is achieved through training graduate students in diverse aspects of science and engineering including semiconductor device design, processing, measurement, and spintronics; and activities designed to broaden understanding by elementary and high-school students, parents, and the general public of the historical importance of scaling in the semiconductor electronics industry and the challenges faced as scaling reaches its end in the next decade.