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: $ 14.4万
• 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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=642097
• 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存储设备，目前仅限于GHz的阅读和写入速度（STT-MRAM）。达到下一个阶段，太赫兹制度的一种方法是使用光子学。我们提出了一个磁光概念，可以提供两个，证明所需的磁开关工作在太赫兹频率的原则，以及理解所需的飞秒时间和纳米级空间分辨率的过程。我们将研究飞秒磁化翻转的纳米制造磁性结构是薄铁磁圆盘的磁涡旋核心。当磁化围绕这个核心循环时，在其中心，磁化点要么“向上”要么“向下”。它们的尺寸约10 nm和完美的稳定性使它们成为在THz频率下工作的磁性数据存储设备的有希望的候选者。在实验上，我们将遵循模拟预测，半周期MV/cm THz脉冲的磁场可用于这些涡核的飞秒自旋开关。为了将该切换步骤与在涡核中心处所需的空间局部化阅读步骤结合联合收割机，太赫兹脉冲将与聚焦到纳米尺度的飞秒X射线脉冲同步。这将使得能够对自旋动力学进行成像，从而在太赫兹频率下对磁化的切换进行成像。为了在太赫兹频率下观察这种磁开关，我们将使用圆偏振fs X射线，应用一种称为X射线磁性圆二色性（XMCD）的技术。通过比较左、右旋圆偏振脉冲在特定吸收边处的透射率，可以得到垂直于涡核平面的磁化分量。该项目将与MPB通信公司合作，开发一种突破性的磁光技术，实现磁涡流存储设备的飞秒开关和阅读。和少周期公司，由来自Technion和庆应义塾大学的国际合作者支持，以扩展下一代数据存储设备的性能。