Spin dynamics of quantum Ising chain in random correlated magnetic fields

Abstract

The spin dynamics of one-dimensional quantum Ising chain with random correlated magnetic fields (RCMFs) is studied at the high-temperature limit by the recursion method. Both the spin autocorrelation function and its corresponding spectral density are investigated under the circumstance of bimodal-type and Gaussian-type RCMFs. It is found that the dynamics of the system are highly dependent on the correlated mode and strength between the longitudinal and transverse magnetic fields (i.e., Bxi and Bzi). Due to the cooperation or synergy effect between Bxi and Bzi, crossovers between different dynamical behaviors can be revealed in most of the cases. In general, the dynamics of the system is dominant by the field (Bxi or Bzi) with a larger proportion when the RCMFs are weak. However, when the RCMFs are strong, the system tends to exhibit a disordered behavior, which manifests as a multiple-peak feature in the bimodal-type case or a broaden spectral in the Gaussian-type case. In another perspective, when the proportion of Bzi is small, the central-peak behavior can be enhanced by increasing the proportion of Bxi. Interestingly, when the proportion of Bzi is large, the perturbation of Bxi on Bzi tends to excite new dynamical behavior. Our results indicate that using RCMF to manipulate the spin dynamics of the Ising system may be a new try.