Femtosecond switching and reading of magnetic vortex memory devices

磁涡旋存储器件的飞秒切换和读取

• 批准号: 494228-2016
• 负责人: Légaré, François
• 金额: $ 12.39万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657113
• 关键词: Femtosecond; switching; reading; magnetic; vortex

Our modern networked society keeps asking for smaller and faster memory devices, which are currently limited to GHz reading and writing speed (STT-MRAM). One way to reach the next stage, the THz regime, is using photonics. We present a magneto-optical concept that can provide both, proof of principle that the required magnetic switching works at THz frequencies, as well as understanding the processes with the required femtosecond temporal and nanoscale spatial resolution. The nanofabricated magnetic structure we will investigate for femtosecond magnetization switching is the magnetic vortex core of thin ferromagnetic discs. While magnetization circulates around this core, at its center the magnetization points either "up" or "down". Their size ~10 nm and perfect stability make them promising candidates for magnetic data storage devices operated at THz frequencies. ** Experimentally, we will follow simulations which have predicted that the magnetic field of a half-cycle MV/cm THz pulse could be used for femtosecond spin switching of these vortex cores. To combine this switching step with the required spatially localized reading step at the center of the vortex core, the THz pulse will be synchronized with a femtosecond X-ray pulse, focussed down to the nanoscale. This will enable to image the spin dynamics and thus the switching of magnetization at THz frequencies. To observe this magnetic switching at THz frequencies, we will use circularly polarized fs X-rays, applying a technique called X-ray magnetic circular dichroism (XMCD). By comparing the transmission between left and right circularly polarized pulses at specific absorption edges, one can retrieve the magnetization component normal to the plane of the vortex core. This project will enable the development of a disruptive magneto-optical technology that enables femtosecond switching and reading of magnetic vortex memory devices in collaboration with MPB Communications Inc. and few-cycle Inc., supported by international collaborators from Technion and Keio University, to scale the performance of the next generation of data storage devices.******

我们的现代网络社会不断要求更小，更快的记忆设备，这些设备目前仅限于GHz读写速度（STT-MRAM）。达到下一个阶段的一种方法是使用光子学。我们提出了一种磁光概念，可以提供既可以提供所需磁开关在THZ频率上有效的原理证明，又可以使用所需的飞秒时间和纳米级空间分辨率来理解过程。我们将为飞秒磁化开关进行调查的纳米制造磁结构是薄铁磁盘的磁涡流核心。磁化强度在该核心周围循环，而在其中心，磁化点要么“向上”或“向下”。它们的尺寸〜10 nm和完美的稳定性使它们成为以THZ频率操作的磁性数据存储设备的有希望的候选者。 **在实验上，我们将遵循模拟，这些模拟预测半周期MV/cm Thz脉冲的磁场可用于这些涡流核的飞秒旋转开关。为了将此切换步骤与涡流核心中心所需的空间局部读取步骤相结合，THZ脉冲将与二秒X射线脉冲同步，重点放在纳米级。这将使旋转动力学成像，从而在THZ频率下进行磁化的切换。为了在THZ频率下观察这种磁开关，我们将使用循环极化的FS X射线，并应用一种称为X射线磁性圆形二色性（XMCD）的技术。通过比较左右圆形极化脉冲之间在特定的吸收边缘的透射，可以将磁化磁化分量垂直于涡流芯的平面。该项目将能够开发一种破坏性的磁光技术，该技术可以与MPB Communications Inc.和少数Cycle Inc.合作进行飞秒的转换和阅读，并在Technion和Keio University的国际合作者支持下，以扩展下一代数据存储设备的性能。