Spin dynamics of the one-dimensional double chain spin-½ antiferromagnet KNaCuP2O7
Dr. Raman Sankar and his group, in collaboration with research groups in the Republic of Korea, especially Prof. Kwang-Yong Choi at Sungkyunkwan University, investigated static and dynamic spin susceptibility of antiferromagnetic material KNaCuP2O7. They combined a muon spin relaxation (μSR) technique with thermodynamic measurements to explore the spin dynamics of one-dimensional (1D) S = ½ antiferromagnetic double chain KNaCuP2O7. They tested the 1D theory by probing spin transport using zero and longitudinal-field μSR. A uniform 1D spin chain model well describes static magnetic susceptibility and specific heat with the intrachain interaction J/kB ≈ 55 K and small interchain interactions. Spin excitations probed by zero-field μSR manifest that high-temperature diffusive spin transport turns into ballistic behavior with decreasing temperature below 30 K. In addition, they observe that longitudinal-field μSR varies hardly with an external magnetic field. The field-independent dynamical spin susceptibility disagrees with diffusive or ballistic behaviors.
WebSite: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.174442