Abstract
We study the ground state and spin excitations in Ba3MnSb2O9, an easy-plane S=5/2 triangular lattice antiferromagnet. By combining single-crystal neutron scattering, electric spin resonance (ESR), and spin wave calculations, we determine the frustrated quasi-two-dimensional spin Hamiltonian parameters describing the material. While the material has a slight monoclinic structural distortion, which could allow for isosceles-triangular exchanges and biaxial anisotropy by symmetry, we observe no deviation from the behavior expected for spin waves in the in-plane 120° state. Even the easy-plane anisotropy is so small that it can only be detected by ESR in our study. In conjunction with the quasitwo dimensionality, our study establishes that Ba3MnSb2O9 is a nearly ideal triangular lattice antiferromagnet with the quasiclassical spin S=5/2, which suggests that it has the potential for an experimental study of Z- or Z2-vortex excitations.
| Original language | English |
|---|---|
| Article number | 174424 |
| Journal | Physical Review B |
| Volume | 108 |
| Issue number | 17 |
| DOIs | |
| State | Published - Nov 1 2023 |
Funding
We thank Tsuyoshi Okubo and Takahiro Misawa for useful discussions. Y.K., Z.Q., and J.M. acknowledge the National Key Research and Development Program of China (Grant No. 2022YFA1402702), and the support by the NSFC (Grants No. U2032213, and No. 12074246). J.M. thanks the financial support from the interdisciplinary program Wuhan National High Magnetic Field Center (Grant No. WHMFC 202122), Huazhong University of Science and Technology. H.W.C. was supported by Hefei Science Center, CAS (Grant No. 2021HSC-KPRD003). Q.H. and H.D.Z. were supported by the National Science Foundation, Division of Materials Research, under Awards No. DMR-2003117. A portion of this research used resources at the High Flux Isotope Reactor and Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory (ORNL).