Quantum critical Tomonaga-Luttinger liquid in the anisotropic triangular antiferromagnet Ca3ReO5Cl2

Abstract We report on a local-probe study of two-dimensional anisotropic triangular antiferromagnet Ca3ReO5Cl2 using 35Cl nuclear magnetic resonance (NMR) and muon spin relaxation (µSR) techniques. The 35Cl spin-lattice relaxation rate obeys a power-law dependence 1/T1∝T1/2K−1 below 20 K and the intra- and interchain spin diffusion constants deduced from LF-µSR are highly anisotropic in their thermal evolution. Our NMR and µSR data evince that the Tomonaga-Luttinger liquid (one-dimensionalization) is driven by anisotropic spin diffusion. Moreover, we observe a universal scaling of T1/2K−1(1/T1) with K = 1 and a time-field scaling (t/Hγ) of the muon spin polarization with γ = 1 − 1/2K = 0.5. These findings instantiate that Ca3ReO5Cl2 with intermediate spatial anisotropy realizes a quantum critical Tomonaga-Luttinger liquid in the zero-field limit.