Coherent Two-Dimensional Terahertz Magnetic Resonance Spectroscopy of Collective Spin Waves

We report a demonstration of two-dimensional (2D) terahertz (THz) magnetic resonance spectroscopy using the magnetic fields of two time-delayed THz pulses. We apply the methodology to directly reveal the nonlinear responses of collective spin waves (magnons) in a canted antiferromagnetic crystal. Th...

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Bibliographic Details
Main Authors: Kurihara, Takayuki, Suemoto, Tohru, Lu, Jian, Li, Xian, Hwang, Harold Y., Ofori-Okai, Benjamin Kwasi, Nelson, Keith Adam
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:English
Published: American Physical Society 2017
Online Access:http://hdl.handle.net/1721.1/110194
https://orcid.org/0000-0002-7706-8121
https://orcid.org/0000-0003-1322-4786
https://orcid.org/0000-0002-0737-6786
https://orcid.org/0000-0001-7804-5418
Description
Summary:We report a demonstration of two-dimensional (2D) terahertz (THz) magnetic resonance spectroscopy using the magnetic fields of two time-delayed THz pulses. We apply the methodology to directly reveal the nonlinear responses of collective spin waves (magnons) in a canted antiferromagnetic crystal. The 2D THz spectra show all of the third-order nonlinear magnon signals including magnon spin echoes, and 2-quantum signals that reveal pairwise correlations between magnons at the Brillouin zone center. We also observe second-order nonlinear magnon signals showing resonance-enhanced second-harmonic and difference-frequency generation. Numerical simulations of the spin dynamics reproduce all of the spectral features in excellent agreement with the experimental 2D THz spectra.