Visualizing magnetic domains with terahertz radiation

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13330
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied materials
• Research Institution: The University of Tokyo
• Principal Investigator: Kida Noriaki 東京大学, 大学院新領域創成科学研究科, 准教授 (30587069)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: テラヘルツ電磁波 / 磁気ドメイン

Outline of Final Research Achievements

We report the terahertz radiations in various polar and ferrimagnetic insulating oxides upon irradiation of a femtosecond laser pulse at room temperature. By the resonant optical excitation of an originally spin-forbidden transitio, we observed the emission of terahertz waves, which is attributable to the magnetic-dipole radiation originating from the light-induced subpicosecond magnetization modulation. By mapping out the emission of the terahertz waves, we successfully visualized the vector images of in-plane magnetic domains in magnetic fields. The terahertz-radiation imaging presented here is useful as a new tool to observe ferro- or ferri-magnetic domains.

Free Research Field

テラヘルツ波物性