SHF: Small: Collaborative Research: Skyrmion Mediated Eenergy-efficient VCMA Switching of 2-Terminal p-MTJ Memory

SHF：小型：合作研究：Skyrmion 介导的 2 端 p-MTJ 存储器的节能 VCMA 切换

基本信息

批准号：
1909030
负责人：
Jayasimha Atulasimha
金额：
$ 25万
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：
2019
资助国家：
美国
起止时间：
2019-10-01 至 2024-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1909030&HistoricalAwards=false
关键词：
SHF Small Collaborative Research Skyrmion

项目摘要

State of the art magnetic memory devices use electrical current to switch the magnetization of a nano-magnet from 'up' to 'down' state or vice versa and thus encode the binary bits 1 and 0 respectively. Unlike devices based on widely-used CMOS (Complementary Metal Oxide Semiconductor) technology, such a device, based on technology called spin transfer torque random access memory (STT-RAM), is non-volatile, a significant advantage. However, these devices consume about 1000 times the energy that CMOS devices use for switching. If electrical field is used to control magnetization, these devices could be a hundred times more energy-efficient. However, development of such control methods are impeded by the level of errors introduced due to the presence of material defects and room temperature thermal noise in the material. This project seeks to demonstrate new techniques that makes the switching and control process robust to such defects, thus achieving the energy savings needed for this technology to be competitive with CMOS devices. The project would also help mentor undergraduate summer research, various K-12 workshops (including a K-12 research experience for underrepresented sections in partnership with Richmond Minorities in Engineering Program) on nano-magnetic computing. This project aims to demonstrate that forcing the magnetization through an intermediate so-called "magnetic skyrmion state", where the magnetization spirals from pointing up/down at the core to pointing down/up at the periphery of a circular nano-magnet, makes the switching process extremely robust as well as eliminates the need for any extra magnetic field. The development of such device, if successful, could make the energy efficient Voltage Control of Magnetic Anisotropy (VCMA) switching technique viable for practical memory devices while needing only modest changes to existing STT-RAM fabrication process. The key technical approach in this research project will address gaps in knowledge as well as demonstrate a proof of concept for skyrmion mediated nano-magnetic memory device. The project plans to 1) investigate the growth of various material systems and interfaces and characterize their magnetic properties to develop an optimized memory device that is energy efficient, scalable and has low switching error, 2) demonstrate proof of concept VCMA switching of a nano-magnetic memory cell ~100 nm diameter mediated by a skyrmion state and characterize its switching error, and 3) perform rigorous modeling of skyrmion mediated magnetization dynamics in the presence of thermal noise and defects to understand why the intermediate skyrmion state makes the magnetization reversal robust and study further scaling of these devices. Students will be trained on complementary thin film growth, nano-fabrication, magnetic characterization and micromagnetic modeling in this project.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.

最先进的磁性内存设备使用电流将纳米磁力的磁化从“向上”转换为“向下”状态，反之亦然，因此分别编码了二进制位1和0。与基于广泛使用的CMO（互补金属氧化物半导体）技术的设备不同，基于称为自旋传输扭矩随机访问记忆（STT-RAM）技术的设备是非挥发性的，这是一个显着优势。但是，这些设备消耗了CMOS设备用于切换的能量的1000倍。如果使用电场来控制磁化，则这些设备可能会增加一百倍。但是，由于材料缺陷的存在和室温热噪声，引入的错误水平阻碍了这种控制方法的发展。该项目旨在展示新技术，从而使转换和控制过程稳健地对此类缺陷，从而实现了该技术与CMOS设备竞争所需的节能。该项目还将帮助指导本科夏季研究，各种K-12研讨会（包括与瑞蒙少数群体在工程计划中合作的K-12研究经验）在纳米磁计算上。该项目的目的是证明，通过中间所谓的“磁性天际状态”迫使磁化强度在其中，磁化强度从向上/向下指向核心，以向下/向下/向上指向/向上指向圆形纳米磁力的外围，使开关过程变得非常强大，并消除了任何额外的磁性领域的需求。如果成功的话，这种设备的开发可以使磁各向异性（VCMA）开关技术的节能电压控制可为实用的存储设备可行，同时仅需要对现有的STT-RAM制造过程进行适度的更改。该研究项目中的关键技术方法将解决知识差距，并展示Skyrmion介导的纳米磁性记忆设备的概念证明。 The project plans to 1) investigate the growth of various material systems and interfaces and characterize their magnetic properties to develop an optimized memory device that is energy efficient, scalable and has low switching error, 2) demonstrate proof of concept VCMA switching of a nano-magnetic memory cell ~100 nm diameter mediated by a skyrmion state and characterize its switching error, and 3) perform rigorous modeling of skyrmion mediated magnetization dynamics in the presence of热噪声和缺陷，以了解为什么中间的天空状态使磁化逆转逆转并研究这些设备的进一步缩放。该项目将对学生进行互补薄膜增长，纳米制作，磁性表征和微磁性建模的培训。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估来进行评估的审查标准。