Dimensional reduction and incommensurate dynamic correlations in the $$S=\frac{1}{2}$$ triangular-lattice antiferromagnet Ca3ReO5Cl2

Abstract

The observation of spinon excitations in the $$S=\frac{1}{2}$$ S = 1 2 triangular antiferromagnet Ca3ReO5Cl2 reveals a quasi-one-dimensional (1D) nature of magnetic correlations, in spite of the nominally 2D magnetic structure. This phenomenon is known as frustration-induced dimensional reduction. Here, we present high-field electron spin resonance spectroscopy and magnetization studies of Ca3ReO5Cl2, allowing us not only to refine spin-Hamiltonian parameters, but also to investigate peculiarities of its low-energy spin dynamics. We argue that the presence of the uniform Dzyaloshinskii-Moriya interaction (DMI) shifts the spinon continuum in momentum space and, as a result, opens a zero-field gap at the Γ point. We observed this gap directly. The shift is found to be consistent with the structural modulation in the ordered state, suggesting this material as a perfect model triangular-lattice system, where a pure DMI-spiral ground state can be realized.

Multistep transitions in spin crossover materials without long-range spin state order from dimensional reduction

“…It is interesting to note that similar mechanisms have also been proposed for the origin of quantum disorder in spin liquids. 61–80…”

“…It is interesting to note that similar mechanisms have also been proposed for the origin of quantum disorder in spin liquids. [61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80] We found that disordered phases with weak short-range correlations produce structure factors that are similar to those of long range spin state ordered phases, which can complicate their experimental identification. Diffuse scattering is only observed when strong short-range correlations are present.…”

Pinalites: Optical Properties and Quantum Magnetism of Heteroanionic A3MO5X2 Compounds

“…Recent high-field ESR measurements have revealed that the spiral magnetic order in CROC is stabilized by uniform DMIs. 51 Because the incommensurate magnetic order stabilized by DMIs is expected to host interesting phenomena such as magnetoelectric effects and magnetic skyrmions, the spiral magnetic order in CROC has garnered interest.…”

“…Another pair of orbital lobes (blue in Figure 3b) is arranged in a staggered manner between adjacent chains with a smaller overlap, resulting in the weak interchain exchange of J′. According to first-principles calculations and subsequent highfield ESR experiments, the J′/J anisotropies were estimated to be 0.295 19 and 0.254, 51 respectively. It should be noted that the direct exchange interactions are sufficiently large even though the transition metals are separated from each other by more than 5 Å.…”