Spin superfluidity in solid antiferromagnets

2017 Fiscal Year Final Research Report

• Project/Area Number: 26400340
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Okinawa Institute of Science and Technology Graduate University
• Principal Investigator: Konstantinov Denis 沖縄科学技術大学院大学, 量子ダイナミクスユニット, 准教授 (50462685)
• Research Collaborator: Bunkov Yu. P.
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: magnetic resonance

Outline of Final Research Achievements

We observed nonlinear nuclear magnetic resonance signals in antiferromagnetic MnCO3 samples at strong microwave pumping. The signals indicated that the conventional model of heating of nuclear spins by microwave pumping can not explain the observed results. We developed a theoretical framework to explain nonlinear nuclear resonance signals at strong microwave pumping. Our approach is based on Landau-Lifshitz-Gilbert equations of motion to describe coupled electron-nuclear spin precession. Comparison of our theory with experiments indicates that under strong microwave pumping the nuclear magnetization vector is deflected by a large angle while preserving its magnitude. This can be identified with the Bose-Einstein condensate of nuclear magnons with coherently and uniformly precesses nuclear spins.

Free Research Field

condensed-matter physics