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TT: Fachverband Tiefe Temperaturen
TT 42: Poster: Correlated Electrons I
TT 42.15: Poster
Wednesday, March 29, 2023, 15:00–18:00, P2/OG2
Field-tuned critical fluctuations in the triangular-lattice delafossite NaYbO2 probed by 23Na NMR — •S. Luther1,2, K. M. Ranjith3,4, D. Opherden1, S. Khim3, H. Yasuoka3, J. Wosnitza1,2, M. Baenitz3, and H. Kühne1 — 1Hochfeld-Magnetlabor Dresden, HZDR — 2Institut für Festkörper- und Materialphysik, TU Dresden — 3MPI-CPfS, Dresden — 4IFW Dresden
The frustrated triangular-lattice delafossite NaYbO2 is a promising candidate for realizing a quantum spin liquid (QSL) ground state. The combination of a strong spin-orbit coupling and crystalline-electric-field effects leads to a magnetic anisotropy and a pseudospin-1/2 state of the Yb3+ ions at low temperatures. The absence of magnetic order and emergence of pronounced low-energy spin fluctuations have been shown by several experimental techniques, such as specific heat, inelastic neutron scattering, and muon spin relaxation. We present 23Na NMR investigations of the low-temperature spin correlations by means of spectroscopy and 1/T1 measurements of polycrystalline NaYbO2. At small magnetic fields and low temperatures, a strongly increased 1/T1 rate, as well as the absence of significant spectral line broadening suggest the presence of a QSL ground state with critical fluctuations at the verge of a magnetic instability. Above about 1 T, a crossover regime with persistent strong spin fluctuations and an onset of static magnetic ordering is observed. For fields above about 2 T, the formation of field-induced long-range magnetic order yields a strongly suppressed 1/T1 rate and an inhomogeneously broadened spectral lineshape.