Energy efficient spin-torque devices

节能自旋扭矩装置

• 批准号: 2230124
• 负责人: Weigang Wang
• 金额: $ 45万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2230124&HistoricalAwards=false
• 关键词: Energy; efficient; spin; torque; devices

In most electronic devices, only the charge of electrons is utilized while another feature spin has unexplored advantages. The spin of electrons is a quantum-mechanical property that offer advantages to achieve future generations of electronics that can operate faster while consuming less energy. To date, most activities in spintronics have largely been focused on ferromagnetic materials where all the spins are aligned in the same direction and is relatively easy to read, write and store information with high fidelity. Currently, it is believed that the manipulation of spin can be even faster and potentially more energy efficient in another class of material called ferrimagnets, where the spins of different atoms point in opposite directions. In this project, the PIs proposes to investigate ferrimagnets-based devices and explore new methods to read and write information. Novel device structures, and theoretical models will be developed. The results of this research will potentially impact a wide range of applications in memory, logic, data storage, neuromorphic computing, and radiofrequency devices. In addition, the project will provide valuable training opportunities for graduate and undergraduate students, specifically from underrepresented and minority groups. In addition, the PIs will actively participate in direct outreach to the public in local or national events.In recent years, ferrimagnets have gained a great deal of attention due to their unique properties. The staggered moments in fully compensated ferrimagnets result in a zero net magnetization, which allows spin currents to penetrate much deeper, a potentially very useful feature in increasing the efficiency of spin-torque switching. Intriguing physics also exists at the angular momentum compensation points of ferrimagnets, where a finite magnetization and nonzero spin polarization persist, enabling the exploration of antiferromagnetic-like fast dynamics in ferrimagnets. In this project, the PIs will carry out a joint experimental-theoretical investigation on devices based on ferrimagnets, specifically, on spin-transfer torque and spin-orbit torque effects where the magnetization can be switched by an electric current. The PIs will develop novel devices where the ferrimagnets will be actively participating in the magnetoresistance and spin angular moment transfer process, instead of only passively providing perpendicular magnetic anisotropy to the system. Both two-terminal and three-terminal devices will be investigated, to understand the spin-transfer torque and spin-orbit torque effects, respectively. The research will be focused on the interaction of spin-polarized tunneling current with the two sublattices of ferrimagnets, to understand the roles of different spin torques (damping-like vs field-like) and to realize possible anti ferromagnetic-like dynamics in switching experiments down to 100ps.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.

在大多数电子设备中，仅利用电子的电荷，而另一种特征自旋具有未开发的优势。电子自旋是一种量子力学特性，它为实现下一代电子产品提供了优势，这些电子产品可以在消耗更少能量的同时运行更快。 迄今为止，自旋电子学的大多数活动主要集中在铁磁材料上，其中所有自旋都沿同一方向排列，并且相对容易以高保真度读取、写入和存储信息。 目前，人们相信，在另一类称为亚铁磁体的材料中，自旋的操纵可以更快，并且可能更节能，其中不同原子的自旋指向相反的方向。 在该项目中，PI 提议研究基于亚铁磁体的设备并探索读取和写入信息的新方法。将开发新的器件结构和理论模型。这项研究的结果可能会影响内存、逻辑、数据存储、神经形态计算和射频设备等领域的广泛应用。此外，该项目还将为研究生和本科生，特别是来自代表性不足和少数群体的研究生和本科生提供宝贵的培训机会。此外，PI还将积极参与地方或国家活动​​中与公众的直接接触。 近年来，亚铁磁体因其独特的性能而受到广泛关注。完全补偿的亚铁磁体中的交错力矩导致净磁化强度为零，这使得自旋电流能够渗透得更深，这对于提高自旋扭矩切换效率来说是一个潜在非常有用的特征。有趣的物理现象也存在于亚铁磁体的角动量补偿点，其中有限磁化强度和非零自旋极化持续存在，使得探索亚铁磁体中类似反铁磁的快速动力学成为可能。 在该项目中，PI将针对基于亚铁磁体的器件进行联合实验理论研究，特别是自旋转移扭矩和自旋轨道扭矩效应，其中磁化强度可以通过电流切换。 PI 将开发新颖的设备，其中亚铁磁体将主动参与磁阻和自旋角矩传递过程，而不是仅仅被动地向系统提供垂直磁各向异性。将研究两端和三端器件，以分别了解自旋转移力矩和自旋轨道力矩效应。研究将集中于自旋极化隧道电流与亚铁磁体两个子晶格的相互作用，以了解不同自旋扭矩（类阻尼与类场）的作用，并在开关实验中实现可能的类反铁磁动力学低至 100ps。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。