Abstract
The two-dimensional triangular-lattice antiferromagnet (TLAF) is a textbook example of frustrated magnetic systems. Despite its simplicity, the TLAF model exhibits a highly rich and complex magnetic phase diagram, featuring numerous distinct ground states that can be stabilized through frustrated next-nearest-neighbor couplings or anisotropy. In this paper, we report low-temperature magnetic properties of the TLAF material CsCeSe2. The inelastic neutron scattering (INS) together with specific heat measurements and density functional theory calculations of crystalline electric field suggest that the ground state of Ce ions is a Kramers doublet with strong easy-plane anisotropy. Elastic neutron scattering measurements demonstrate the presence of stripe-yz magnetic order that develops below TN=0.35K, with the zero-field ordered moment of mCe≈0.65μB. Application of magnetic field first increases the ordering temperature by about 20% at the intermediate field region and eventually suppresses the stripe order in favor of the field-polarized ferromagnetic state via a continuous quantum phase transition (QPT). The field-induced response demonstrates sizable anisotropy for different in-plane directions, Ba and Ba, which indicates the presence of bond-dependent coupling in the spin Hamiltonian. We further show theoretically that the presence of anisotropic bond-dependent interactions can change the universality class of QPT for Ba and Ba.
| Original language | English |
|---|---|
| Article number | 054445 |
| Journal | Physical Review B |
| Volume | 110 |
| Issue number | 5 |
| DOIs | |
| State | Published - Aug 1 2024 |
Funding
We thank Dr. Hongtao Liu (Instrument Analysis & Research Center, Sun Yat-sen University) for the assistance with LA-ICP-TOF measurements and data evaluations. We thank Dr. Jong Keum for the help with the x-ray Laue and x-ray diffraction measurements, Dr. Feng Ye for assistance with single-crystal x-ray diffraction measurements, Dr. J\u00F6rg Sichelschmidt for the attempts of the ESR measurements and for the helpful discussion. Work at Sun Yat-sen University was supported by the National Natural Science Foundation of China (Grant No. 12304187), the open research fund of Songshan Lake Materials Laboratory (Grant No. 2023SLABFN30), the Guangzhou Basic and Applied Basic Research Funds (Grant No. 2024A04J4024), and the Fundamental Research Funds for the Central Universities, Sun Yat-sen University (Grant No. 23qnpy57). Work at Oak Ridge National Laboratory (ORNL) was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. This research used resources at the Spallation Neutron Source and the High Flux Isotope Reactor, DOE Office of Science User Facilities operated by the Oak Ridge National Laboratory. X-ray Laue and XRD measurements were conducted at the Center for Nanophase Materials Sciences (CNMS) (CNMS2019-R18) at ORNL, which is a DOE Office of Science User Facility. The pulsed magnetic field magnetometry measurements at National High Magnetic Field Laboratory are supported by the U.S. DOE, Office of Science, via BES program \u201CScience of 100 Tesla\u201D. The work of A.L.C. on the analytical theory was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0021221.
| Funders | Funder number |
|---|---|
| Basic Energy Sciences | |
| Division of Materials Sciences and Engineering | |
| Oak Ridge National Laboratory | |
| Office of Science | |
| Fundamental Research Funds for the Central Universities | |
| Guangzhou Basic and Applied Basic Research Funds | 2024A04J4024 |
| National Natural Science Foundation of China | 12304187 |
| U.S. Department of Energy | DE-SC0021221 |
| Sun Yat-Sen University | 23qnpy57 |
| open research fund of Songshan Lake Materials Laboratory | 2023SLABFN30 |