Spin dynamics of the one-dimensional double chain spin-1/2 antiferromagnet KNaCuP2O7

We combine a muon spin relaxation (mu SR) technique with thermodynamic measurements to explore the spin dynamics of one-dimensional (1D) S = 1/2 antiferromagnetic double chain KNaCuP2O7. Static magnetic susceptibility and specific heat are well described by a uniform 1D spin chain model with the intrachain interaction J/k(B) approximate to 55 K and small interchain interactions. Spin excitations probed by zero-field mu SR evince that high-temperature diffusive spin transport turns into ballistic behavior with decreasing temperature below 30 K. In addition, we observe that longitudinal-field mu SR varies hardly with an external magnetic field. The field-independent dynamical spin susceptibility disagrees with diffusive or ballistic behaviors.

Automated summary

We combine μSR technique with thermodynamic measurements to explore the spin dynamics of one-dimensional S = 1/2 antiferromagnetic double chain KNaCuP2O7. Results show that the high-temperature diffusive spin transport turns into ballistic behavior below 30K. In addition, longitudinal-field μSR varies hardly with an external magnetic field.