Nunes, M.E.S.; Plascak, J.A.; Florencio, J. - In: Physica A: Statistical Mechanics and its Applications 332 (2004) C, pp. 1-14
We investigate the Hamiltonian dynamics of two low-dimensional quantum spin systems in a random field, at the infinite-temperature limit: the XY chain and the two-leg XY ladder with interchain Ising interactions. We determine the longitudinal spin autocorrelation functions of the spin-12XY chain...