Two-dimensional THz Spectroscopy of Multiferroic BiFeO3

Multiferroic materials exhibit coupling between spin, lattice, and electronic degrees of freedom, and the ability to enhance these interactions to drive multiferroic properties may be the key to future high-speed, low-power technologies. We apply two-dimensional (2D) terahertz (THz) spectroscopy to examine these couplings in multiferroic BiFeO
₃
. With extreme excitation using high-field THz light, 2D THz spectroscopy can reveal how anharmonic phonon-magnon coupling results in coherent energy transfer between modes and can potentially lead to experimental extraction of phonon-magnon coupling constants.