Description
Takayuki Kurihara, Research Fellow (Assistant Professor) at the Institute for Solid State Physics, The University of Tokyo, is an experimentalist in ultrafast laser physics. His work is concerned with the investigation of condensed matter at ultrafast timescales. His research interests include R&D of the ultrafast optical techniques, terahertz and infrared sources, ultrafast spintronics and other condensed-matter systems. Dr. Kurihara received his bachelor’s degree from the Department of Engineering, The University of Tokyo. Thereafter he joined the group led by Professor Tohru Suemoto, and received his master of science and Ph.D. degrees in science from the Department of Physics, The University of Tokyo, in 2013 and 2016, respectively. During his Ph.D. course, he was enrolled in The Advanced Leading Graduate Course for Photon Science, and awarded a JSPS fellowship. He has also received a number of the best presentation prizes and awards. 1. Introduction 1.1 Terahertz (THz) Control of a Magnetic System 1.2 Field Enhancement Using Metallic Subwavelength Structures 1.3 Purpose and Outline of This Thesis 2. Technical Background 2.1 Rare-Earth Orthoferrites (RFeO3) 2.2 Generation and Detection of THz Pulses 2.3 THz Magnetic Nearfields in a Split-Ring Resonator (SRR) 3. Resonant Enhancement of Spin Precession by SRR-Induced Magnetic Nearfields and Interactive Energy Transfer 3.1 Sample Fabrication 3.2 Experiment Configuration and Measurement Setup 3.3 Result 1: Resonant Enhancement of FM Mode Precession 3.4 Result 2: Interactive Energy Transfer Between SRR and Spin 3.5 Chapter Summary 4. Control of Macroscopic Magnetic Order Dynamics Using SRR-Enhanced THz Magnetic Fields 4.1 Background: Controlling the Path of Phase Transition by the Coherent Spin Precession 4.2 Motivation 4.3 Experiment Setup / Sample Properties 4.4 Results 4.5 Chapter Summary 5. Numerical Simulation of the Macroscopic Domain Formation 5.1 Brief Summary of Important Features Observed in Chapter 4 5.2 Simulation of Magnetization Dynamics Using LLG Equation and Free- Energy Model 5.3 Mechanism of Domain Creation by THz Magnetic Fields 5.4 Chapter Summary 6. Conclusion 6.1 Summary 6.2 Future Prospects Appendix. Relation Between the s- and m- Parameters
