Coherent detection of hidden spin–lattice coupling in a van der Waals antiferromagnet

Journal Article · Tue Mar 14 00:00:00 EDT 2023 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.2208968120· OSTI ID:1961430

Ergeçen, Emre ^[1]; Ilyas, Batyr ^[1]; Kim, Junghyun ^[2]; Park, Jaena ^[2]; Yilmaz, Mehmet Burak ^[1]; Luo, Tianchuang ^[1]; Xiao, Di ^[3]; Okamoto, Satoshi ^[4]; Park, Je-Geun ^[2]; Gedik, Nuh ^[1]

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1. Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
2. Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea, Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
3. Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, Department of Physics, University of Washington, Seattle, WA 98195
4. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831

Strong interactions between different degrees of freedom lead to exotic phases of matter with complex order parameters and emergent collective excitations. Conventional techniques, such as scattering and transport, probe the amplitudes of these excitations, but they are typically insensitive to phase. Therefore, novel methods with phase sensitivity are required to understand ground states with phase modulations and interactions that couple to the phase of collective modes. Here, by performing phase-resolved coherent phonon spectroscopy (CPS), we reveal a hidden spin–lattice coupling in a vdW antiferromagnet FePS ₃ that eluded other phase-insensitive conventional probes, such as Raman and X-ray scattering. With comparative analysis and analytical calculations, we directly show that the magnetic order in FePS ₃ selectively couples to the trigonal distortions through partially filled t _{2 g} orbitals. This magnetoelastic coupling is linear in magnetic order and lattice parameters, rendering these distortions inaccessible to inelastic scattering techniques. Our results not only capture the elusive spin–lattice coupling in FePS ₃ but also establish phase-resolved CPS as a tool to investigate hidden interactions.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1961430
• Alternate ID(s): OSTI ID: 1965270
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 12 Vol. 120; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of Sciences
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS