Switchable Persistent Spin Helix Devices

可切换的持续自旋螺旋装置

• 批准号: 2314614
• 负责人: Jian Shi
• 金额: $ 45万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2314614&HistoricalAwards=false
• 关键词: Switchable; Persistent; Spin; Helix; Devices

Power dissipation and energy consumption are a key limiting factor in the future scalability of present computing technologies based on silicon field-effect transistors. Due to their potential for a low switching energy, spintronic devices that leverage the spin of electrons to carry information instead of their charge have long been pursued as an alternative approach, both for digital computing and analog devices. However, realizing the potential of spintronic devices requires overcoming a few basic challenges. First, weak spin-orbit coupling in conventional spintronic materials such as GaAs necessitates transport of electrons over large devices to allow control of the spin. In contrast, using a material with high spin-orbit coupling to make smaller devices leads to rapid loss of spin information due to dephasing: spins rapidly rotating and becoming out of phase with each other. The PIs propose to address these two challenges by leveraging materials with a special class of spin behavior called the persistent spin helix, where electron spins remain in phase even when rotating rapidly, enabling spin information to be retained longer even in high spin-orbit materials. Specifically, by using electric-field tunable persistent spin helix in van der Waals solids with strong spin-orbit coupling, the PIs propose to enable a new class of materials for spintronic devices, where the spin behavior can be sensitively controlled by electric fields and where the device dimensions can be reduced by two to three orders of magnitude due to the significantly stronger spin-orbit coupling. This would help innovate the design of competitive spin field-effect transistors for high-performance and low-power computing. This award also aims to promote research training to historically underrepresented groups in the rapidly growing field of spintronic materials and devices, and thereby contribute to both the technical knowhow and workforce for the development of future microelectronics.The PIs propose to understand the effect of electric field-tuned symmetry and Hamiltonian on the spin texture, spin dynamics, and spin transport of square van der Waals crystals with strong spin-orbit coupling for spintronic devices. With the square symmetry of the basal plane and natural quantum well structures of selected materials, when an external electric field is applied along desired crystallographic orientations, persistent spin helix-type spin-orbit field is expected. With persistent spin helix states and strong spin-orbit coupling, the PIs expect to achieve electric field/electric voltage-switchable symmetry-protected long-range coherent spin transport. The model materials include air-stable, lithography-friendly van der Waals crystals Bi2O2Se and BiOI, and the model devices include persistent spin helix-based spin field effect transistors. The proposed approach for enabling and tuning persistent spin helix does not require careful balance between Rashba and Dresselhaus fields commonly seen in III-V. This makes the proposed model systems a robust platform for exploring spin field effect transistor. The PIs will grow single crystalline orientation-controlled spintronic tetragonal van der Waals semiconductors and fabricate persistent spin helix-based field effect transistors. The PIs will computationally predict and experimentally reveal the spin-polarized band structure, and dynamics and wavelength of persistent spin helix in the model materials and devices. The PIs will also demonstrate the proof-of-concept persistent spin helix-based field effect transistors and reveal the effects of device structure/dimension, gate dielectrics, external voltage/polarization, and temperature on the characteristics and performance of the spin field effect transistor.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.

功率耗散和能源消耗是基于硅现场效应晶体管的当前计算技术的未来可扩展性的关键限制因素。由于它们具有低开关能量的潜力，因此长期以来一直将利用电子自旋携带信息而不是电荷的自旋设备作为数字计算和模拟设备的替代方法。但是，意识到自旋设备的潜力需要克服一些基本挑战。首先，在常规的自旋材料（例如GAAS）中弱的自旋轨道耦合需要电子在大型设备上运输，以控制自旋。相比之下，使用具有高自旋轨道耦合的材料使较小的设备导致速度迅速丢失自旋信息，因此旋转迅速旋转并彼此之间变得过时。 PI提议通过利用特殊类别的自旋行为来解决这两个挑战，称为“持续自旋螺旋”，即使在迅速旋转时，电子旋转仍处于相位状态，从而使自旋信息甚至在高自旋轨道材料中也可以保留更长的时间。 Specifically, by using electric-field tunable persistent spin helix in van der Waals solids with strong spin-orbit coupling, the PIs propose to enable a new class of materials for spintronic devices, where the spin behavior can be sensitively controlled by electric fields and where the device dimensions can be reduced by two to three orders of magnitude due to the significantly stronger spin-orbit coupling.这将有助于创新竞争性旋转场效应晶体管的设计，以实现高性能和低功率计算。该奖项还旨在促进研究培训，以在历史上迅速增长的旋转材料和设备领域中代表性不足的群体中促进研究培训，从而为未来的微电子学的发展提供了技术知识和劳动力。自旋设备。随着基础平面的平方对称性和所选材料的天然量子井结构，当沿所需的晶体学方向应用外部电场时，预计持续的旋转螺旋型自旋轨道场。凭借持续的自旋螺旋状态和强旋轨耦合，PIS希望实现电场/电压切换对称性保护的长距离连贯旋转转运。模型材料包括气稳定，光刻的范德华晶体晶体BI2O2SE和BIOI，模型设备包括持续的基于自旋螺旋的自旋场效应晶体管。提出的启用和调整持续旋转螺旋的方法不需要在III-V中通常看到的Rashba和Dresselhaus田地之间进行仔细的平衡。这使提出的模型系统成为探索自旋场效应晶体管的强大平台。 PI将生长单晶方向控制的自旋四角形范德华半导体，并制造持续的基于自旋螺旋的磁场效应晶体管。 PI将在计算上预测和实验揭示自旋极化带结构，以及模型材料和设备中持续自旋螺旋的动力学和波长。 PI还将展示概念验证持续的基于旋转螺旋的现场效应晶体管，并揭示设备结构/维度，栅极介电，外部电压/极化以及温度对旋转场效应晶体管的特征和性能的影响。该奖项反映了NSF的法定任务，并通过评估范围来审查概念的支持。