Year: 2026
Type: article
Abstract: Strong-field terahertz (THz) excitations enable dynamic control over electronic, lattice and symmetry degrees of freedom in quantum materials. Here, we uncover pronounced terahertz-induced symmetry modulations and coherent phonon dynamics in the van der Waals antiferromagnet MnPS 3 , in which inversion symmetry is broken by its antiferromagnetic spin configuration. Our time-resolved second harmonic generation measurements reveal long-lived giant oscillations in the antiferromagnetic phase, with amplitudes comparable to the equilibrium signal, driven by phonons involving percent-level atomic displacements relative to the equilibrium bond lengths. The temporal evolution of the rotational anisotropy patterns indicates a dynamic breaking of mirror symmetry, modulated by two vibrational modes at 1.7 THz and 4.5 THz, with the former corresponding to a hidden mode not observed in equilibrium spectroscopy. These effects arise in part from a field-induced charge rearrangement mechanism that lowers the local crystal symmetry and couples to the phonon modes. We uncover a long-lived field-driven response with a complex THz polarization dependence, consistent with a metastable state of reduced symmetry. Through comparison with simulations, we interpret this response in terms of a potential antiferromagnetic-to-ferrimagnetic transition. Our results establish an effective field-tunable pathway for driving excitations otherwise weak in equilibrium.
Source: Nature Communications
Authors: Sheikh Rubaiat Ul Haque, Martin J. Cross, Sangeeta Rajpurohit, Jonah B. Haber, Christopher J. Ciccarino, Alexandra C. Zimmerman, Isabelle J. Sealey, Vadym Kulichenko, Monique Tie, Huaiyu Wang, Sharon S. Philip, Choongwon Seo, Jake D. Koralek, Luis Balicas, Mykhaylo Ozerov, Dmitry Smirnov, Liang Z. Tan, Felipe H. da Jornada, Tadashi Ogitsu, Matthias C. Hoffmann, Tony F. Heinz, Aaron M. Lindenberg
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funder: State of Florida
OpenAlex ID: W4414808545