Two-dimensional terahertz spectroscopy as a tool for revealing nonlinear interactions in media

K A Grishunin; V R Bilyk; E D Mishina; A V Kimel; E A Mashkovich

doi:10.1063/5.0138253

Two-dimensional terahertz spectroscopy as a tool for revealing nonlinear interactions in media

Rev Sci Instrum. 2023 Jul 1;94(7):073005. doi: 10.1063/5.0138253.

Authors

K A Grishunin¹, V R Bilyk^{1

2}, E D Mishina², A V Kimel¹, E A Mashkovich³

Affiliations

¹ Institute for Molecules and Materials, Radboud University, 6525AJ Nijmegen, The Netherlands.
² Department of Nanotechnology, MIREA - Russian Technological University, Prospekt Vernadskogo, 78, 119454 Moscow, Russia.
³ Institute of Physics II, University of Cologne, Cologne D-50937, Germany.

PMID: 37498165
DOI: 10.1063/5.0138253

Abstract

Usually, the presence of multiple eigenstates (magnons and phonons) in a system makes it difficult to analyze the coupled excitation mechanism using conventional single-pulse terahertz (THz) spectroscopy. On the contrary, 2D THz spectroscopy reveals energy flows between these states, which facilitates the identification of the coupled dynamics. In this article, we provide a theoretical description of this advanced technique and an experimental demonstration of its performance in antiferromagnet CoF2. Here, 2D THz spectroscopy shows that the THz pulse induces energy transfer from the magnon mode to the Raman-active phonon mode via a nonlinear excitation pathway.