Development of microwave device using Bose-Einstein condensation at magnon system

2015 Fiscal Year Final Research Report

• Project/Area Number: 24656236
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Okayama University
• Principal Investigator: Mino Michinobu 岡山大学, 自然科学研究科, 准教授 (30222326)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: マグノン / 非線形緩和 / マイクロ波放射 / ボーズ凝縮

Outline of Final Research Achievements

Bose Einstein condensation of a magnon system driven by microwave at room temperature has been reported with using the Brillouin light scattering technique. Another effective experiment about a nonequilibrium magnon system is to study microwave radiations from a parametrically excited sample. As a viewpoint of developing new nonlinear microwave devices, microwave radiation from parametrically excited magnons was studied experimentally. Parallel pumping excitations and transverse pumping at the first-order Suhl instability were carried out on a ferromagnetic yttrium iron garnet (YIG). A high sensitivity microwave circuit was used to detect spectra of radiation microwave. At high pumping power, multi-frequency components are observed simultaneously. The spectra depend on static field, or magnetostatic modes. These spectra and the time series of microwave radiation show that a four-magnon scattering is important in a nonlinear relaxation process.

Free Research Field

物性実験