Investigating the magnetic manipulation of the terahertz emission from spintronic structures.

从简单的双层铁磁/重金属双层结构中发射出中到远红外光谱范围的极宽带电磁辐射，为产生太赫兹（THz）辐射的单周期脉冲开辟了令人兴奋的新途径。该研究项目的总体目标是优化基于自旋的铁磁结构，以发射太赫兹辐射，并揭示控制这些新系统特性的物理原理。通过了解基本的发射过程，这项工作有可能直接影响太赫兹辐射未来商业应用的发展，并为开发下一代自旋电子器件建立新的表征工具。本博士的特别重点是对自旋电子源的太赫兹发射的磁操纵的研究，特别是自旋电子双层结构的磁饱和行为，以发展我们对外加磁场如何控制自旋电子结构平面上的磁化强度以及这反过来如何控制太赫兹发射特性的基本理解。这是特别相关的新太赫兹发射方案利用磁场整形源极化控制。据报道，来自场成形装置内自旋电子结构的强纵向太赫兹分量的起源也将是一个特别的研究领域，具有开发太赫兹传播模型以补充实验测量的潜力。本博士课程将涉及激光光谱学技术、高功率激光放大系统和计算机数据采集包的使用。将为学生提供全面的培训，以建立使用这些系统的能力和专业知识。学生将熟悉基于自旋电子学的太赫兹发射器和太赫兹探测系统，偏振分辨电光太赫兹探测装置的设计和建造将是这项工作的关键步骤。该学生将在培养早期职业研究人员所必需的技能方面得到充分支持，包括准备和提交第一作者论文，以便在高影响力期刊上发表这项工作的进展，并在重要的国家和国际会议（例如MMM-Intermag和IRMMW-THz）上发表演讲，从而满足EPSRC培养下一代熟练研究人员的职责。本项目涉及EPSRC的以下研究领域：凝聚态物质、磁性和磁性材料、光子材料、射频和微波器件、自旋电子学

The emission of extremely broadband electromagnetic radiation spanning from the mid- to far-infrared spectral regime from simple bilayer ferromagnetic/heavy metal bilayer structures has opened up exciting possibilities to a new route for the generation of single-cycle pulses of terahertz (THz) radiation. The overarching aim of this research project is to optimise spin-based ferromagnetic structures for the emission of THz radiation and to reveal the physics that governs the properties of these novel systems. By understanding the fundamental emission process, this work has the potential to directly influence the development of future commercial applications for THz radiation and to establish new characterization tools for use in developing the next generation of spintronic devices. The particular focus of this PhD is an investigation into the magnetic manipulation of the THz emission from spintronic sources, in particular the below magnetic saturation behaviour of spintronic bilayer structures, to develop our fundamental understanding of how the applied magnetic field controls the magnetization across the plane of the spintronic structure and how this in turn controls the THz emission characteristics. This is of particular relevance to novel THz emission schemes utilizing magnetic field shaping for source polarization control. The origin of the reported strong longitudinal THz component from a spintronic structure within a field shaping setup will also be a particular area of investigation, with the potential to develop THz propagation modelling to complement the experimental measurements. This PhD will involve the use of laser spectroscopy techniques, high power laser amplifier systems and computerized data acquisition packages. Full training will be provided to the student to build competence and expertise in the use of these systems. The student will develop familiarity with spintronic-based THz emitters and THz detection systems and the design and construction of a polarization resolved electro-optic THz detection setup will be a key step in this work. The student will be fully supported in developing the skills essential to early career researchers, including preparation and submission of first author papers for publication of progress in this work in high impact journals and in the delivery of presentations at key national and international conferences (for example MMM-Intermag and IRMMW-THz), thus meeting the remit of EPSRC to train the next generation of skilled researchers.This project relates to the following EPSRC research areas:- Condensed matter: magnetism and magnetic materials- Photonic materials- RF and microwave devices- Spintronics