Abstract
Magnetic structures and spin excitations are studied across the phase diagram of the geometrically frustrated S=3/2 quantum antiferromagnet Cs2CoBr4 in magnetic fields applied along the magnetic easy axis, using neutron diffraction, inelastic neutron scattering, and terahertz absorption spectroscopy. The data are analyzed, where appropriate, using extended SU(4) linear spin wave theory. A minimal magnetic Hamiltonian is proposed based on measurements in the high-field paramagnetic state. It deviates considerably from the previously considered models. Additional dilatometry experiments highlight the importance of magnetoelastic coupling in this system.
| Original language | English |
|---|---|
| Article number | 104433 |
| Journal | Physical Review B |
| Volume | 109 |
| Issue number | 10 |
| DOIs | |
| State | Published - Mar 1 2024 |
Funding
One of the authors (A.Z.) would like to thank Professor Giamarchi (University of Geneva) and Professor Coldea (University of Oxford) for illuminating discussions. This research was funded in part by a MINT grant “Tricoordinated frustrated quantum magnets” of the Swiss National Science Foundation. It made use of resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We acknowledge support by the Estonian Research Council Grants No. PRG736 and No. MOBJD1103, and by European Regional Development Fund Project No. TK134. Experiments at the ISIS Neutron and Muon Source were supported by beam time allocation from the Science and Technology Facilities Council (). This research benefited from neutron beam time at the instrument D23 at the Institute Laue Langevin provided via the collaboration agreement between the French Alternative Energies and Atomic Energy Commission (CEA) and the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and funded by the Swiss State Secretariat for Education, Research, and Innovation (SERI).