Frustrated Quantum Magnet Cs<sub>2</sub>CoBr<sub>4</sub>: magnetoelastic phenomena
Oral-In-person
Abstract
Cs2CoBr4 is a quantum antiferromanet with strong frustration of interactions and local anisotropies. It features a complex magnetic phase diagram with the presence of an incommensurate spin density wave, magnetization plateau and incommensurate fan phases (Ref. [2] and Ref. in there). It is also famous for having a spectacular "Zeeman ladder"-type excitation spectrum (Ref.[1]).
Preliminary magnetostriction measurements revealed pronounced anomalies at all phase boundaries (Ref.[2]). This indicates strong magnetoelastic coupling in this compound. In this talk I will present comprehensive dilatometry as well as sound velocity and attenuation measurements performed across the entire H-T phase diagram. We propose an exchange-striction model that quantitatively reproduces the main experimental features.
[1] L. Facheris, S. D. Nabi, A. Glezer Moshe, U. Nagel, T. R˜o om, K. Yu. Povarov, J. R. Stewart, Z. Yan, and A. Zheludev. Confinement of fractional excitations in a triangular lattice antiferromagnet. Phys. Rev. Lett., 130:256702, Jun 2023.
[2] L. Facheris, S. D. Nabi, K. Yu. Povarov, Z. Yan, A. Glezer Moshe, U. Nagel, T. Röm, A. Podlesnyak, E. Ressouche, K. Beauvois, J. R. Stewart, P. Manuel, D. Khalyavin, F. Orlandi, and A. Zheludev. Magnetic field induced phases and spin hamiltonian in Cs2CoBr4. Phys. Rev. B, 109:104433, Mar 2024.
Preliminary magnetostriction measurements revealed pronounced anomalies at all phase boundaries (Ref.[2]). This indicates strong magnetoelastic coupling in this compound. In this talk I will present comprehensive dilatometry as well as sound velocity and attenuation measurements performed across the entire H-T phase diagram. We propose an exchange-striction model that quantitatively reproduces the main experimental features.
[1] L. Facheris, S. D. Nabi, A. Glezer Moshe, U. Nagel, T. R˜o om, K. Yu. Povarov, J. R. Stewart, Z. Yan, and A. Zheludev. Confinement of fractional excitations in a triangular lattice antiferromagnet. Phys. Rev. Lett., 130:256702, Jun 2023.
[2] L. Facheris, S. D. Nabi, K. Yu. Povarov, Z. Yan, A. Glezer Moshe, U. Nagel, T. Röm, A. Podlesnyak, E. Ressouche, K. Beauvois, J. R. Stewart, P. Manuel, D. Khalyavin, F. Orlandi, and A. Zheludev. Magnetic field induced phases and spin hamiltonian in Cs2CoBr4. Phys. Rev. B, 109:104433, Mar 2024.
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Presenters
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Viola Romerio
- ETH Zurich