相关实验视频
Updated: Jun 23, 2025
07:45
Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
10.8K
全光旋转切换在超快的时间尺度上
Wolfgang Hübner1, Georgios Lefkidis1, G P Zhang2
1Department of Physics, Rheinland-Pfälzische Technische Universität, Kaiserslautern-Landau, 67653 Kaiserslautern, Germany.
概括
全光自旋切换 (AOS) 提供使用激光脉冲的超快磁性存储解决方案. 本综述总结了AOS十年的实验和理论进展,探讨了它对未来技术的潜力.
科学领域:
- 物理 物理学 物理
- 材料科学 材料科学 材料科学
- 信息技术 信息技术 信息技术
背景情况:
- 对于更快,更密集的磁性存储的需求是由信息技术革命推动的.
- 全光学旋转切换 (AOS) 是一个有前途的解决方案,它只使用激光脉冲,独立于磁场,可以在1-10比秒内逆转磁化.
- 存在两个主要机制:螺旋体依赖 (HD-AOS) 和螺旋体独立 (HID-AOS).
研究的目的:
- 在过去十年中,回顾全光旋转交换 (AOS) 的主要实验和理论发展.
- 为新研究人员提供介绍,为该领域的经验丰富的科学家提供摘要.
- 突出AOS技术在实际应用方面的进展.
主要方法:
- 对各种磁性材料中单脉冲和多脉冲切换的实验发现的综述.
- 分析研究AOS的基本机制的理论模型.
- 关于影响切换动态的材料特异性和激光特异性研究的汇编.
主要成果:
- 在了解和控制各种磁性材料中的AOS方面取得了重大进展.
- 虽然一些合金允许单脉冲切换,但大多数需要多个激光脉冲.
- 材料和激光性能极大地影响开关效率和速度,尽管确切的机制仍在争论中.
结论:
- 十年的研究已经推进了AOS,使该领域更接近磁性存储的实际应用.
- 需要对基本机制进行进一步的研究,以优化AOS性能.
- 对于下一代数据存储技术来说,AOS具有显著的潜力.
相关概念视频
01:08Spin–Spin Coupling Constant: Overview
908
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
908
01:03Atomic Nuclei: Nuclear Spin State Overview
922
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
922
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
998
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
998
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.0K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.0K
01:08Atomic Nuclei: Nuclear Spin
1.8K
All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although protons and neutrons in nuclei may have higher half-integer spins owing to energetic factors.
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not...
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not...
1.8K
01:30Propagation Speed of Electromagnetic Waves
3.4K
Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:
3.4K