SHF: Small: Collaborative Research: Energy Efficient Strain Assisted Spin Transfer Torque Memory

SHF：小型：合作研究：节能应变辅助自旋转移扭矩存储器

• 批准号: 1815033
• 负责人: Jayasimha Atulasimha
• 金额: $ 36万
• 依托单位: Virginia Commonwealth University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1815033&HistoricalAwards=false
• 关键词: SHF; Small; Collaborative; Research; Energy; SHF; Small; Collaborative; Research; Energy

Non-volatile random access memory (NV-RAM) is often built with a device called spin transfer torque random access memory (STT-RAM), the main constituent of which is a circular nano-magnet. A bit is "written" into the nano-magnet by passing a spin-polarized current whose polarity determines whether bit "1" or bit "0" is written. The energy barrier between these states prevents the magnetization from switching spontaneously due to thermal noise, making the device non-volatile. Unfortunately, the energy dissipated in the writing current is 100-1000 times more than the energy dissipated in today's CMOS devices, which is a large cost to pay for non-volatility. This project seeks to demonstrate that temporarily reducing the energy barrier between the "up" and "down" magnetization states with surface acoustic waves (SAW) can significantly lower the current needed to write a bit and reduce the energy dissipation by orders of magnitude. This would make the SAW-assisted STT-RAM ideal for embedded processors, internet of things, large data centers and cyber-physical systems requiring low energy memory. At least 3 PhD students would be trained on the techniques of complementary nano-fabrication, nano-characterization and computer modeling. The investigators will hold a nano-magnetism workshop for high school students and will host under-represented K-12 students in their labs for a summer month, as well as leverage the "Nano-Days" program to reach out to high school students. The key technical approach in this research project will involve the following complementary experimental and modeling research directions: (i) Modeling the combined effect of strain and spin transfer torque (STT) on the magnetization switching in the presence of thermal noise (ii) Experimental demonstration of strain induced reduction in STT write current in optimized devices (guided by the modeling effort) (iii) Proof-of-concept demonstration of acoustic wave induced reduction in STT write current. The knowledge generated by this research would lead to better understanding of the combined effect of strain and spin torque on switching nano-magnetic memory elements and the switching probability in the presence of thermal noise. If successful, it would demonstrate a low energy paradigm for writing information in non-volatile nano-magnetic memory devices.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.

非挥发性随机访问存储器（NV-RAM）通常是使用称为自旋传输随机访问存储器（STT-RAM）的设备构建的，其主要成分是圆形纳米磁铁。通过传递旋转偏振电流，其极性决定位“ 1”或BIT“ 0”写成，将一点点“写入”。这些状态之间的能量屏障可防止磁化因热噪声而自发切换，从而使设备无挥发性。不幸的是，写作电流中消散的能量是当今CMOS设备中消散的能量的100-1000倍，这是为非挥发性支付的巨大成本。该项目试图证明，具有表面声波（SAW）的“向上”和“向下”磁化状态之间的能屏障可以显着降低写入所需的电流并通过数量级减少能量消散所需的电流。这将使锯齿辅助的STT-RAM非常适合嵌入式处理器，物联网，大数据中心和网络物理系统，需要低能记忆。至少有3名博士生将接受有关互补纳米制作，纳米特征和计算机建模技术的培训。调查人员将为高中生举办纳米磁性研讨会，并将在他们的实验室中接待人数不足的K-12学生，并利用“纳米天”计划与高中生联系。该研究项目中的关键技术方法将涉及以下互补实验和建模研究方向：（i）建模应变和自旋转移扭矩（STT）对存在热噪声的磁化切换的综合效果（II）菌株诱导的菌株诱导的STT写入电流减少的实验证明（III ICECTINCE）（III）的范围（III）的范围（III）的重建（III）的重建（III）的重建（III）均可进行。这项研究产生的知识将使人们更好地理解应变和自旋扭矩对切换纳米磁性记忆元件的综合效果以及在存在热噪声的情况下的开关概率。如果成功，它将证明在非挥发性纳米磁性记忆设备中编写信息的低能范式。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准的评估来通过评估来支持的。